Aug 17, 2006 - List of Figures vi . . List of Tables . ..... Egypt has long been famous for its Eocene marine mammals .... The standard work on Bivalvia is that of Oppenheim ..... T. Barron's (1907) study, published posthumously, is important ...
MARINE MAMMALS (CETACEA AND SIRENIA) FROM THE EOCE: :E OF GCI EL MOKATTAM AND FAYUM, EGYPT: STRATIGRAPHY, AGE, AND PALEOENVIRONMENTS PHILIP D. GINGERICH
PAPERS ON PALEONTOLOGY
- RECENT NUMBERS
Systematics of the Fissiculate Blastoidea by D. Bradford Macurda (1983) Epizoans on the Brachiopod Paraspirfer bownockeri (Stewart) from the Middle Devonian of Ohio by Diana K. Sparks, Richard D. Hoare, and Robert V. Kesling (1980) Early Cenozoic Paleontology and Stratigraphy of the Bighorn Basin, Wyoming by Philip D. Gingerich (ed.) and others (1980) Dimorphic Middle Devonian Paleocopan Ostracoda of the Great Lakes Region by Robert V. Kesling and Ruth B. Chilman (1987) The Clarkforkian Land-Mammal Age and Mammalian Faunal Composition across the Paleocene-Eocene Boundary by Kenneth D. Rose (198 1) The Evolutionary History of Microsyopoidea (Mammalia, ?Primates) and the Relationship between Plesiadapiformes and Primates by Gregg F. Gunnel1 (1989) New Earliest Wasatchian Mammalian Fauna from the Eocene of Northwestern Wyoming: Composition and Diversity in a Rarely Sampled High-Floodplain Assemblage by Philip D. Gingerich (1989) Evolution of Paleocene and Eocene Phenacodontidae (Mammalia, Condylarthra) by J. G. M. Thavissen (1990) Marine Mammals (Cetacea and Sirenia) from the Eocene of Gebel Mokattam and Fayum, Egypt: Stratigraphy, Age, and Paleoenvironments by Philip D. Gingerich (1992)
Museum of Paleontology The University of Michigan Ann Arbor, Michigan 48 109-1079
MARINE MAMMALS (CETACEA AND SIRENIA) FROM THE EOCENE OF GEBEL MOKAVAM AND FAYUM, EGYPT: STRATIGRAPHY, AGE, AND PALEOENVIRONMENTS
Frontispiece: Geological map of Eocene and Oligocene at Gebel Mokattam and Gebel Ahmar east of the great Citadel of Cairo, reproduced from Schweinfurth (1883). North is toward lower left of map. Schweinfurth's locality XU behind Tingiye Mosque (Gama Tingiye) in zone A l e has produced many fossil vertebrates.
MARINE MAMMALS (CETACEA AND SIRENIA) FROM THE EOCENE OF GEBEL MOKATTAM AND FAYUM, EGYPT: STRATIGRAPHY, AGE, AND PALEOENVIRONMENTS
Museum of Paleontology The University of Michigan Ann Arbor, Michigan 48 109-1079
UNIVERSITY OF MICHIGAN PAPERS ON PALEONTOLOGY NO. 30
Papers on Paleontology No. 30 Museum of Paleontology The University of Michigan A m Arbor, Michigan 48109-1079
Philip D. Gingerich, Director
Published June 30, 1992
TABLEOFCONTENTS
. . . . . . . . . . . . . . . . . . . . . . . . ii Title page . . . . . . . . . . . . . . . . . . . . . . . .iii Table of Contents . . . . . . . . . . . . . . . . . . . . v List of Figures . . . . . . . . . . . . . . . . . . . . . . vi .. List of Tables . . . . . . . . . . . . . . . . . . . . . . v: Abstract . . . . . . . . . . . . . . . . . . . . . . . . ix
Bown and Kraus . . . . . . . . . . . . . . . . 37 Other authors . . . . . . . . . . . . . . . . . 38 Summary . . . . . . . . . . . . . . . . . . . . 38
Frontispiece
I
.
................... Nomenclature of invertebrate fossils . . . Acknowledgments . . . . . . . . . . . . . . History of Study: Gebel Mokattam . . . . Fraas . . . . . . . . . . . . . . . . . . . . . . Introduction
.
I1
.
I11
V 1 1 3
7 7 Bauerman and Le Neve Foster . . . . . . . 7 Zittel . . . . . . . . . . . . . . . . . . . . . . 7 Schweinfurth . . . . . . . . . . . . . . . . . 7 Mayer-Eymar . . . . . . . . . . . . . . . . . 8 Fourtau . . . . . . . . . . . . . . . . . . . . . 8 Blanckenhorn . . . . . . . . . . . . . . . . . 9 Barron . . . . . . . . . . . . . . . . . . . . . 13 Krasheninnikov and Ponikarov . . . . . . . 13 Strougo . . . . . . . . . . . . . . . . . . . . . 15 Abdel-Kireem . . . . . . . . . . . . . . . . . 16 Other authors . . . . . . . . . . . . . . . . . 16 Summary . . . . . . . . . . . . . . . . . . . .16
. . . . . . . . . . 17 Schweinfurth . . . . . . . . . . . . . . . . . 17 Mayer-Eymar . . . . . . . . . . . . . . . . . 22 Blanckenhorn . . . . . . . . . . . . . . . . . 22 Beadnell . . . . . . . . . . . . . . . . . . . . 30 Vondra . . . . . . . . . . . . . . . . . . . . . 34 Strougo . . . . . . . . . . . . . . . . . . . . . 36 Abdou and Abdel-Kireem . . . . . . . . . . 37 Haggag . . . . . . . . . . . . . . . . . . . . .37
History of Study: Fayum
.
IV New Observations in Fayum . . . . . . . . . 41
.
Garet el-Esh . . . . . . . . . . . . . . . . . . 41 Garet Umm Rig1 . . . . . . . . . . . . . . . . 41 Wadi Hitan . . . . . . . . . . . . . . . . . . . 42 Geometry of Birket Qarun Formatio~; . . . 46 Members of Qasr el-Sagha Formation . . . 51 Geographic trends . . . . . . . . . . . . . . .54
. . . . . . 55 Western Desert . . . . . . . . . . . . . . . . 55 Cairo-Giza . . . . . . . . . . . . . . . . . . . 55 Eastern Desert . . . . . . . . . . . . . . . . . 56 Fayum . . . . . . . . . . . . . . . . . . . . . . 57 Sinai . . . . . . . . . . . . . . . . . . . . . . . 59 Age of Fayum formations . . . . . . . . . . 59
Sea Level Sequence Stratigraphy
. Interpretation of Paleoenvironments
. . . . 63 Gehannam Formation . . . . . . . . . . . . . 63 Birket Qarun Formation . . . . . . . . . . . 63 Qasr el-Sagha Formation . . . . . . . . . . . 64 Hard beds . . . . . . . . . . . . . . . . . . 64 Temple Member . . . . . . . . . . . . . . 65 Dir Abu Lifa Member . . . . . . . . . . 65 Umm Rig1 Member . . . . . . . . . . . . 66 Harab Member . . . . . . . . . . . . . . . 66 Gebel Qatrani Formation . . . . . . . . . . . 66 Progradation of environments . . . . . . . . 67
VI
.
. . . . . . . 71 Cetacea . . . . . . . . . . . . . . . . . . . . . 71 Sirenia . . . . . . . . . . . . . . . . . . . . . - 7 4 Ages and paleoenvironments . . . . . . . . 76 Taxon longevity . . . . . . . . . . . . . . . . 77
VII Marine Mammals and Localities
VIII.Conclusions and Prospectus Literature cited
. . . . . . . . . . 79
. . . . . . . . . . . . . . . . . . . . . . 81
LIST OF FIGURES Figure
w e
1, Geological map of northeastern Egypt . . . . . 2 2. Location map of Gebel Mokattam and Fayum . . . . . . . . . . . . . . . . . . . . . . 4-5 3. Schweinfurth's geological section near Cairo . 8 4. Eocene stratigraphy of Gebel Mokattam: modern interpretation by Strougo . . . . . . . 10 5. Eocene stratigraphy of Gebel Mokattam: early interpretation by Schweinfurth . . . . . 11 6. Eocene stratigraphy of Gebel Mokattam: early interpretation by Fourtau . . . . . . . . 12 7. Eocene stratigraphy of Gebel Mokattam: early interpretation by Blanckenhorn . . . . . 13 8. Eocene stratigraphy at Wadi el-Sheikh interpreted by Blanckenhorn . . . . . . . . . . 14 9. Eocene stratigraphy at Gebel Ahmar in Cairo interpreted by Blanckenhorn . . . . . . 15 10. Eocene stratigraphy at Gebel Kibli el-Ahram in Giza interpreted by Blanckenhorn . . . . . 15 11. Eocene stratigraphy at Tamariskenbucht in Fayum interpreted by Blanckenhorn . . . . . 18 12. Eocene stratigraphy at Gebel Achdar in Fayum interpreted by Blanckenhorn . . . . . 18 13. Eocene stratigraphy at Klippenecke in Fayum interpreted by Blanckenhorn . . . . . . . . . . 19 14. Eocene stratigraphy at Qasr el-Sagha in Fayum interpreted by Blanckenhorn . . . . . 19 15. Eocene stratigraphy at Gebel Hameier in Fayum interpreted by Blanckenhorn . . . . . 20 16. Eocene stratigraphy at Korallenhiigel in Fayum interpreted by Blanckenhorn . . . . . 21 17. Eocene stratigraphy at Kamelpass in Fayum interpreted by Blanckenhorn . . . . . . . . . . 22 18. Eocene stratigraphy at Zeuglodonberg in Fayum interpreted by Blanckenhorn . . . . . 23 19. Sketch of Zeuglodonberg locality in Fayum published by Blanckenhorn . . . . . . . . . . . 24 20. Eocene stratigraphy at Zeuglodonberg NW in Fayum interpreted by Blanckenhorn . . . 24 21. Eocene stratigraphy at Garet el-Naqb in Fayum interpreted by Blanckenhorn . . . . . 25 22. Eocene stratigraphy at Wadi Ramliya in the Eastern Desert interpreted by Blanckenhorn . . . . . . . . . . . . . . . . . . . . . . . . 26 23. Eocene stratigraphy at Minqar el-Rayan in Fayum interpreted by Beadnell . . . . . . . . 27 24. Eocene stratigraphy at Garet Gehamam in Fayum interpreted by Beadnell . . . . . . . . 28
25. Eocene stratigraphy at west end of Birket Qarun in Fayum interpreted by Beadnell . . 29 26. Birket Qarun escarpment at west end of lake Birket Qarun . . . . . . . . . . . . . . . . 30 27. Eocene stratigraphy at Geziret el-Qarn in Fayum interpreted by Beadnell . . . . . . . . 31 28. Eocene stratigraphy on the mainland opposite Geziret el-Qarn interpreted by Beadnell . . . 31 29. Eocene stratigraphy at Qasr el-Sagha in Fayum interpreted by Beadnell . . . . . . . . 32 30. Eocene stratigraphy at Dir Abu Lifa in Fayum interpreted by Beadnell . . . . . . . . 33 31. Eocene stratigraphy at Wadi Efreet in Fayum interpreted by Bown and Kraus . . . . . . . . 39 32. New stratigraphic section at Garet el-Esh in Fayum . . . . . . . . . . . . . . . . . . . . . 4 0 33. New stratigraphic section at Garet Umm Rig1 in Fayum . . . . . . . . . . . . . . . . . . . . . 4 2 34. New stratigraphic section at Wadi Hitan locality ZV-54NW in Fayum . . . . . . . . . 43 35. New stratigraphic section at Wadi Hitan locality ZV-54 in Fayum . . . . . . . . . . . . 43 36. New stratigraphic section at Wadi Hitan locality ZV-70 in Fayum . . . . . . . . . . . . 44 37. New stratigraphic section at Wadi Hitan locality Sandouk el-Borneta in Fayum . . . . 45 38. Nummulite and oyster beds capping Birket Qarun Formation at Sandouk el-Borneta . . 45 39. Cliffs of Birket Qarun sandstone in Minqar el-Hut escarpment south of Wadi Hitan . . . 46 40. New stratigraphic section at Minqar el-Hut in Fayum . . . . . . . . . . . . . . . . . . . . . 4 7 41. New stratigraphic section at Minqar Abyad northwest of Wadi Hitan . . . . . . . . . . 48-49 42. University of Michigan camp and Camp White Layer in Wadi Hitan, Fayum . . . . . 50 43. Interpretative cross-section of Birket Qarun barrier bar complex in Wadi Hitan . . . . . 51 44. Distribution of Birket Qarun and Qasr el-Sagha formations and facies in northernFayurn . . . . . . . . . . . . . . . . . . . . 52 45. Comparison of Fayum and Gebel Mokattam sections measured by Blanckenhorn . . . . . 53 46. Camp White Layer in Wadi Hitan with rodlike mangrove pneumatophores at surface . 57 47. Cross-section of Camp White Layer mangrove in Wadi Hitan . . . . . . . . . . . . . . . . . . 5 7
LIST OF FIGURES (cont.) Figure
w e
. . . 58
48. Pelvis of Moeritherium from Wadi Hitan 49. Tree trunk in Wadi Hitan bored by Teredo
. . 58
50. Detail of tree trunk bored by Teredo showing . . . . . .. 59 celestite filling of borings 51. Cracks in femur of Bmilosaurus from Wadi Hitan . . . . . .59 52. Stratigraphic correlation chart for Eocene and Oligocene of northern Egypt . . . . 61
. ... . . . . . . .... ... . . ..
53. Hard bed in Temple Member of Qasr el-Sagha Formation at Garet el-Esh 54. Carbonate masses weathering from Umm Rig1 Member east of Dimeh . 55. Stratigraphic model to explain sequence of strata and paleoenvironments at Gebel Mokattam . ... ... 56. Stratigraphic model to explain sequence of strata and paleoenvironments in Fayum
. . . . . 64 . . . . . . . . . 67
..... . ..
.
. . . . .68 . . . 69
LIST OF TABLES Table -
1. Eocene Cetacea of Egypt
w e
. . . . . . . . . . . . . 73
2. Eocene Sirenia of Egypt
. . . . . . . . . . . . . 75
ABSTRACT Gebel Mokattam and Fayum are well known among vertebrate paleontologists for their rich and diverse faunas of Eocene marine mammals. Ten cetacean and seven sirenian species have been named from these two areas. The Eocene stratigraphy of each is reviewed here, and Fayum stratigraphy is supplemented with new observations. The Mokattam Formztion and most of the Giushi Formation at Gebel Mokattam are Lutetian and Bartonian (middle Eocene) in age, and these record deposition offshore in marine shelf and shallow shelf environments. The Maadi Formation at Gebel Mokattam is Priabonian (late Eocene) in age, and was deposited in nearshore and lagoonal environments. The Wadi Rayan Formation and most of the Gehannam Formation in Fayum are Lutetian and Bartonian (middle Eocene) in age, and were deposited offshore in marine shelf and shallow shelf environments. The Birket Qarun Formation is earliest Priabonian (late Eocene) in age, and represents a long linear barrier bar complex buried during marine transgression. The Qasr el-Sagha Formation is Priabonian (late Eocene) in age, and most of it was deposited in lagoonal environments. The Qasr el-Sagha Formation is divided into four members: a shallow outer lagoonal Umm Rig1 Member (new), a deeper central lagoonal Harab Member (new), a shallow inner lagoonal Temple Member, and, at the top, a non-lagoonal Dir Abu Lifa Member. The latter is interpreted to have been deposited on or near the fronts of submarine deltas and in interdeltaic nearshore marine environments. A dynamic stratigraphic model is developed relating sedimentary formations and facies in Fayum to sea level and sea level change. Middle and late Eocene formations at Gebel Mokattam and Fayum were deposited in similar environments, but Gebel Mokattam formations are thinner than their Fayum equivalents and Gebel Mokattam sediments accumulated farther offshore. Comparisons to date indicate that six of the ten Eocene cetacean species described from Egypt are valid, and these represent at least five genera (Dorudon osiris is placed in the new genus Saghacetus). The cetaceans evolved rapidly and show no particular association with paleoenvironments. There are at least three valid species and possibly three genera of sirenians in the Eocene of Egypt. Eotheroides and Protosiren may have inhabited open shallow shelf environments while Eosiren inhabited lagoons, but interpretation is limited because here again genera are rarely known from the same environment at different times or different environments at the same time.
INTRODUCTION
.
Egypt has long been famous for its Eocene marine mammals, Sirenia and Cetacea, which have come principally from two areas: (1) Gebei Mokattam and nearby hills just east of Cairo, and (2) northwestern Fayum 100 km southwest of Cairo (see maps in Figs. 1 and 2). The first sirenian to be described was Eotherium [now Eotheroides] aegyptiacum named by Richard Owen in 1875 from Gebel Mokattam. The first cetaceans were found by G. Schweinfurth in 1879 on the island of Geziret el-Qarn in Fayum. In following years both areas yielded important specimens of Cetacea and Sirenia, and the named types are listed in Tables 1 and 2 at the end of this study. The taxonomic and morphological diversity of Eocene cetaceans and sirenians in Egypt cannot be evaluated without understanding their geological age and the diversity of environments they inhabited. This information is required too for proper comparison with Eocene Cetacea and Sirenia known elsewhere. The Eocene of Egypt has been intensively studied for a long time (Blanckenhorn, 1921; Said, 1962, 1990), and the stratigraphy is unexpectedly complicated. This is due in part, ironically, to excellent exposures over a very broad area permitting sedimentary units to be studied in unusual detail. The literature is diff~cultbecause it is large and scattered, having been written in several languages and published on three continents over a period spanning more than 100 years. More serious, perhaps, is a long tradition of interpretation of geological formations as time slices accumulating like layers on an idealized country-wide stratigraphic cake. It is impossible to substitute a fully developed dynamic model for all the Eocene of Egypt, but it is clear that a dynamic model is required because sea level rose and fell while sedimentary formations in Egypt accumulated on the edge of a passively subsiding continental margin. Two geological formations have yielded important marine mammals at Gebel Mokattam: the Mokattam Formation and the overlying Giushi Formation. Four formations have yielded marine mammals in Fayum: the marine Gehannam, Birket Qarun, and Qasr el-Sagha formations, and, in the case of one sirenian, the predominantly continental Gebel Qatrani Formation.
The history of study of these formations is presented in detail because earlier workers made many important geological observaiions and published stratigraphic sections that are essential for any comprehensive interpretation. The history of study of the Gebel Mokattam area is summarized first in Chapter 11, followed by a summary for the Fayum area in Chapter 111. New observations and new stratigraphic sections in Fayum are presented in Chapter 1V. Sea level sequence stratigraphy and implications for the geological age of the Gebel Mokattam and Fayum deposits are discussed in Chapter V. Paleoenvironrnental interpretations of each of the Eocene formations at Gebel Mokattam and in Fayum are reviewed in Chapter VI. These formations have long been recognized as shallow marine deposits, but, to my knowledge, they have never been integrated into a single comprehensive stratigraphic model. After five seasons of field work in the Fayum, it has been possible to develop a dynamic model relating the Gehannam, Birket Qarun, and Qasr el-Sagha formations of Fayum to each other, and the model is extended to include formations at Gebel Mokattam. A review of the named species of Eocene Cetacea and Sirenia is included in Chapter MI. The species and their ranges are not yet as well known as one would like, and there is as yet only limited association of particular species with particular environments. Finally, Chapter VIII provides a summary of general conclusions and a brief prospectus for future work. NOMENCLATURE OF INVERTEBRATE FOSSILS The Eocene of Egypt is rich in invertebrate fossils, and these are important for interpretation of paleoenvironments. Mayer-Eymar (1883, 1898, 1900, etc.), Oppenheim (1903-1906), and Fourtau (1913) are among the many older authors who described Eocene invertebrates from Egypt. Many names used by early authors have been revised subsequently, and I have made some attempt to update these when possible (but invertebrate nomenclature is not a focus of this work).
1
MEDITERRANEAN SEA
Lake\Burullus
1
FIG. 1-Geological map of northeastern part of Egypt showing location of Fayum-Gebel Mokattam (FayumCairo) area studied here (Fig. 2). Modern depositional settings in northern Egypt include open marine environments of the Mediterranean Sea, barrier-and-lagoon environments of Lake Burullus and other lagoons, active submarine delta fronts fed by the Rosetta and Damietta branches of the River Nile, and the fluvial continental coastal plain of the Nile Delta itself. Eocene sedimentary rocks (medium shading) were deposited in a similar north-southenvironmentalsequenceincludingopen marine, barrier-and-lagoonor delta, backed by continental coastal plain. These transected an ancient coastline trending WSW-ENE like part of the present Egyptian coast. Note that lagoons and active delta fronts at river mouths alternate from east to west today, and the same was probably true in the Eocene. Abstracted from Geological Map of Egypt, scale 1:2000000 (Geological Survey of Egypt, 1981).
The standard work on Bivalvia is that of Oppenheim (1903-1906). Strougo (1988) published a very useful summary of current bivalve nomenclature, with ranges of the forms found at Gebel Mokattam and elsewhere near Cairo. Important taxa include Carolia placunoides, an isodont anomiacean bivalve (not an oyster) with large, thin, flat valves. The genus has a broader range, but Strougo limits the species C. placunoides to the late Mokattamian Stage (Priabonian). Plicatula polymorpha is an isodont pectinacean bivalve that ranges from early through late Mokattamian. Oysters are schizodont rather than isodont, and Egyptian Eocene oyster species placed i: "Ostreatt cr "Gryphaea" by earlier zxthors are now considered to represent Crassostrea, Cubitostrea, Nicaisolopha, Ostrea (Turkostrea), or Pycnodonte. Many bivalves have narrow environmental tolerances, making them useful for paleoenvironmental interpretation but at the same time poor index fossils for correlation. The standard work on Gastropoda is also Oppenheim (1903-1906), and I am not aware of any recent reviews. Nummulites are benthic foraminifera that typically have rather localized geographic distributions and hence limited potential for correlation on a broad scale. Cuvillier (1930) wrote a major review, and he and others have supplemented this subsequently. Nummulites gizehensis is a conspicuously large middle Eocene nummulite several centimeters in diameter that is usually found in Lutetian sediments but may range upward into the Bartonian as well. Roman and Strougo (1988) reviewed Eocene echinoids of greater Cairo. The most widely studied Egyptian microfossils useful for worldwide correlation are planktonic foraminifera, which are not nearly as common as the larger benthic nummulites but evidently can be found when large enough samples of marine sediment are processed. These live in open marine waters but are less often found in nearshore or lagoonal environments. Bolli (1957) and Blow (1979) published the standard zonation widely used in Egypt and elsewhere (see also Toumarkine and Luterbacher, 1985). Important studies in Egypt include Krasheninnikov and Ponikarov (1965), Abdou and Abdel-Kireem (1975), Abdel-Kireem (1985), .Haggag (1985,1989,1990), and Haggag and Luterbacher (1991).
ACKNOWLEDGMENTS I thank Drs. D. C. Fisher and B. Wilkinson, University of Michigan, for discussion and literature on bamer
bars and other shallow marine sedimentary environments and structures; Dr. Fisher for information on calcareous sponges, corals, and hardgrounds; Dr. C. E. Badgley, University of Michigan, for information on bone weathering; Dr. J. Kappelman, University of Texas, for showing me his preliminary interpretation of paleomagnetic stratigraphy; and Dr. A. Seilacher, Tiibingen and Yale universities, for discussion of Kerunia. Drs. D. P. Domning, Howard University, and A. Miller, University of Cincinnati, provided information on callianassid shrimp and their association with seagrass beds. Dr. R. Feldmam, Kent State University, identified the Lobocarcims. Research on E o c e o ~Cetacea has been carried out jointly with Dr. B. H. Smith of the University of Michigan. Dr. Domning reviewed the sirenian systematics included in Table 2. Dr. T. M. Bown, U. S. Geological Survey, generously provided maps and other information when this project started, and he was the first to identify mangrove in Wadi Hitan when we worked there together in 1985. Drs. D. C. Fisher and G. F. Gunnell read and improved the entire text. Drs. T. M. Bown, J. Kappelman, D. T. Rasmussen, J. Van Couvering, and Messrs. W. Clyde, W. Sanders, and M. Uhen reviewed a draft of Chapter V. I thank Drs. B. el-Khashab, Cairo Geological Museum, Cairo; K. Fischer and H. Jaeger, Museum f i r Naturkunde der Humboldt-Universitiit, Berlin; J. Hooker, Natural History Museum, London; E. Heizmam, Staatliches Museum f i r Naturkunde, Stuttgart; V. Fahlbusch and K. Heissig, Universitiits-Institut und Staatssammlung f i r Palbntologie und Historische Geologie, Munich, for access to collections in their care. Mr. Ali Barakat, Dr. T. M. Bown, Dr. G. F. Gunnell, Messrs. M. Hilal, A. A. Abdul Latif, A. Van Nievelt, W. J. Sanders, El-Said Hashem Sherif, and Dr. B. Holly Smith worked with me in Fayum one or more seasons in 1983, 1985, 1987, 1989, and 1991. Specimens illustrated here were prepared by W. J. Sanders. Figures 1-3, 43-45, and 55-56 were drawn or redrawn by B. Miljour. This project was carried out in cooperation with Mme. Dr. Ferial El Bedewi of the Cairo Geological Museum and Geological Survey of Egypt, and with Dr. E. L. Simons and P. Chatrath of Duke University. It is a special pleasure to acknowledge Dr. Simons' encouragement and interest in this research. Financial support in 1987, 1989, and 1991 was provided by the Committee for Research and Exploration of the National Geographic Society, Washington (grants numbered 3424-86, 4154-89, and 4624-91).
'OO'N
FIG. 2-Geological map of Gebel Mokattam and Fayum showing localities and formationsdiscussed in the text. Solid circles mark location of stratigraphic sections in following figures. North is at
30°45'E
31 "00'E
31 "15'E
top of map. Marks on inside of border are 10 km UTM hatchures. Solid black is basalt. Geology from Beadnell(1905) and Geological Survey of Egypt (1981, 1983).
HISTORY OF STUDY: GEBEL MOKATTAM
The Eocene of Egypt was first studied at Gebel Mokattam. This mountain has always been a conspicuous landmark in Caiio, rising east of the Old City and providing a ready source of stone for building construction. The building stone is Eocene in age, some of it is richly fossiliferous, and as a result Gebel Mokattam and its quarries were seemingly studied by every nineteenth century geologist and paleontologist to visit the city. Contributions by nineteenth and twentieth century authors are summarized in the following pages. Fraas Otto Fraas (1867) divided the Gebel Mokattam Eocene into four units: (1) a lower Callianassa bank and nummulite beds; (2) a building stone interval with endocasts of the gastropod Cerithium giganteum and crabs including Lobocarcinus; (3) a 25 m interval with the echinoid Conoclypus, large nummulites identified as Nummulites gizehensis, and clay; and (4) an upper interval rich in oysters and Turritella. These units appear to correspond approximately to what are now called the Lower Building Stone Member of the Mokattam Formation, the Upper Building Stone Member, the Giushi Formation, and the Maadi Formation. Fraas visited a place on the north side of Gebel Mokattam called Moses' Spring (Ain Musa), where he reported sirenian bones (never described) and described the uppermost limestone as containing echinoids. He mentioned this bed as being overlain by the red sands of Gebel Ahmar. Ain Musa is important because the "Ain Musa" echinoid bed can be traced 100 km southwestward to the Fayum and 100 km eastward to the Gulf of Suez. Bauemuzn and Le Neve Foster The following year Bauerman and Le Neve Foster (1868) published a more detailed section of the Gebel Mokattam Eocene, dividing a part of the sequence into lower "white beds" 36 m thick and upper "brown beds" 17 m thick. Bauerman and Le Neve Foster were particularly interested in a unit 1 m or so thick at the top of the brown beds that is unusually rich in celestite ("celestine" [strontium sulphate]), which they postulated to reflect
precipitation from sea water concentrated by evaporation. This unit is in what is today called Giushi Formation. Zittel Two important works appeared in 1883, one by Karl von Zittel and the other by Georg Schweinfurth. Zittel's monograph was his report on geological investigations undertaken during the Rohlfs Expedition of 1873-74 exploring much of the eastern and western deserts of Egypt. Zittel (1883) divided the Eocene into three stages, the "Libysche Stufe" (early Eocene), "Mokattam Stufe" (middle and late Eocene), and "Ober Eocaen" (Oligocene). He divided 95 m of section at Gebel Mokattam into 35 m of white limestone overlain by about 60 m of dark brown or reddish strata. He subdivided the Mokattam Stufe into (1) building stone with celestite, 10 m; (2) porous limestone with large Nummulites gizehensis in the lowest bed and clay, gypsum, and celestite nodules at the top, 25 m; and (3) brown clay shale lacking large nummulites, but with Ostrea, Carolia, and other bivalves. These are approximately the Mokattam, Giushi, and Maadi formations of later authors. Zittel published a colored map summarizing his geological observations and those of earlier explorers. This covered Egypt from Siwa in the west to the Gulf of Suez in the east, and from Cairo in the north to Dakhla and Kharga in the south. Surprisingly, the northern and western Fayum remained largely uncolored as a "geologisch unbekanntes Gebiet" [geologically unknown region] in spite of its proximity to Cairo. Those of us working in a mechanized age must be grateful for Zittel's note with the scale of the map: "Kamelstunden 3% bis 4% Kilometerw-one camel-hour of travel time corresponds to about 4 km of distance, providing the factor necessary to relocate fossil sites specified by early authors in terms of bearing and camel-hour travel time from some prominent landmark (Osborn, 1907a,b, also mentioned such a conversion). Schweintnh The most comprehensive early study of Gebel Mokattam stratigraphy was published in 1883 by Georg Sch-
FIG. 3-Schweinfurth's (1883) geological cross section of the west face of Gebel Mokattam near Cairo. Section was constructed east of the Mohammed Ali Mosque and the Citadel1 of Cairo using landmarks located by triangulation and elevations determined by barometer. Principal stratigraphic subdivisions are lettered A2 through AAAa, following Schweinfurth (see section in Fig. 4). Redrawn from Schweinfurth (1883, Plate XXI). "Pholaden"are mollusks that bore holes in rock, here indicating high PlioPleistocene sea stands.
weinfurth, who was already famous by this time as an East African explorer. Schweinfurth's paper was illustrated by a colored geological map of Gebel Mokattam (reproduced here on the cover and frontispiece), two colored cross sections, and a colored perspective drawing. One of the cross sections is reproduced in Figure 3. Current interpretation of the Gebel Mokattam section is shown in Figure 4, taken from Strougo (see below). Schweinfurth (1883) adopted a system for labelling strata that worked first from bottom up, starting with A at the base and proceeding through AAAA at the top. However, Schweinfurth then discussed and numbered or lettered beds within each of these units from top down, which is inexplicably confusing. Schweinfurth's stratigraphic section and his system for lettering and numbering beds are shown in Figure 5. Like others before him, Schweinfurth divided the Mokattam section into a lower "white" section (A in his scheme) and an upper "brown" or "dark" section (AAA), separated by a relatively thin transitional interval (AA). These divisions (with different names) and Schweinfurth's thicknesses are approximately those recognized today by the Geological Survey of Egypt (1983).
Mayer-Eymur Karl Mayer-Eymar (1886) was the next to study the Gebel Mokattam section. He was Swiss and following two weeks of observation in the field attempted to subdivide the Mokattam section into units corresponding to those recognized in Europe. He correlated all of the Mokattam section with beds exposed in the Paris Basin and thus considered the section to be "Parisian" ("Lutetian" or "middle Eocene") as opposed to "Londinian" ("early Eocene") or "Bartonian" ("late Eocene"). Mayer-Eymar provided no measurements of lithological sections, nor any illustrations. Fourtau RenC Fourtau (1897) published a brief summary description of the stratigraphy of Gebel Mokattam, including a schematic stratigraphic section similar to Schweinfurth's but with a total thickness only about onehalf that reported by Schweinfurth. Fourtau's section is redrawn here in Figure 6 . It was originally published to introduce paleuntological work of Priem (1897a,b), and Fourtau did not bother to compare his thicknesses with those of Schweinfurth nor to explain how these were
determined. Fourtau's section is included to show how different the same section can appear when described by different authors. This is true for thickness, and it is also true in terms of lithology and recorded fossils. Fourtau (18 9 9 , like Mayer-Eymar (1886), regarded the entire Gebel Mokattam section as Lutetian ("Parisian" or "middle Eocene"). He compared beds in the Gebel Mokattam section to the Calcaire grossier infkrieur (beds N-L), Calcaire grossier moyen (beds K-H), and upper Lutetian (Calcaire grossier supkrieur, beds G-A) of the Paris Basin. In his 1897 paper, Bed K, the Nummulites gizehensis member of the Mokattam, was regarded as ese22rice f~!lo-ng notice of a possSb!e palm seed and anecdotal reports of palm leaves being found in this bed. Later Fourtau (1900) developed a rather limited dynamic model involving sea level change. In the later study, the bed K palm was forgotten in favor of Fraas' (1867, p. 128) report of palms ("Apeibopsis gigantea") from the "building stone" interval. This led Fourtau to regard building stone as a local shallow or regressive facies, limestone with Lobocarcinus crabs as a littoral facies, and nummulitic limestone as an open-ocean facies vaci2s de haute mer). He then interpreted the sequence from (1) nummulitic limestone, to (2) building stone, to (3) Lobocarcinus limestone, and back to (1) nummulitic limestone in the Gebel Mokattam section as a full cycle of sea level change. Fourtau deserves credit for being the first to propose a dynamic stratigraphic model to explain this distribution of facies, but the model was interpreted backwards. Building stone is the deeper open-ocean facies . Blanckenhorn Max Blanckenhorn was employed as a Geological Survey of Egypt geologist from 1897 until 1899, during which time he made a thorough study of Paleogene stratigraphy in the vicinity of Cairo (Blanckenhorn, 1900; published after he moved to Pankow near Berlin). Blanckenhorn (1900) divided the "Mokattamstufe" into a lower "light" Mokattam consisting of about 120-180 m of white or yellow-white limestone with siliceous flint beds and also clays, marls, and glauconitic marls, and an upper "dark" Mokattam consisting of 60-70 m of yellow and blue gypsum and celestite clays, marls, dirty limestones, sandy limestones, and sandstones. The "light" Mokattam was also referred to as Gizehensis-Stufe, and the "dark" Mokattam as Carolia-Stufe. The Gebel Mokattam section described by Blanckenhorn (1903, p. 370) is redrawn in Figure 7. L i e Mayer-Eymar and Fourtau before him, Blanckenhorn regarded the entire Mokattam sequence as being equivalent to the Calcaire grossier and thus of Parisian or Lutetian age. Blanckenhorn measured a stratigraphic section of the lower Mokattam in Wadi el-Sheikh in the Eastern Desert near Maghagha 150 km south of Cairo. This section,
shown graphically in Figure 8, was subdivided into five units (I-1 through 1-5). While the Wadi el-Sheikh section was not measured anywhere near Gebel Mokattam, it yielded five subdivisions that were later applied to the lower Mokattam in Cairo (Blanckenhorn, 1903). Much of Blanckenhorn's (1900) report was devoted to the upper or "dark" Mokattam, for which he developed an eight-fold subdivision (Ii-1 through 11-8). Unlike the five-part division of the lower Mokattam, Blanckenhorn's eight-part division of the upper Mokattam was developed at Gebel Mokattam itself. The eight subdivisions were as follows: 4-20 m, hard limestone with Cardium, Lucina, and Turritella, no Carolia and few Plicatula 6-8 m, variegated clay 3-6 m, sandy limestone with Carolia, Turritella (upper Carolia horizon) 2-3 m, oyster banks and gypsiferous calcareous shale (carbonaceous shale and oyster horizon) 3 m, Plicatula horizon 2-3 m, Carolia (lower Carolia horizon, cliff-forming) 5-6 m, small nummulites and gastropods 9 m, gypsiferous clay shale and hard shale ("Tafle" or Tafla) with celestite. [TafZais an Arabic name for a particular kind of clay or claystone.]
-
These units differ slightly from those recognized by Schweinfurth (1883). Blanckenhorn (1900) constructed the sequence at Gebel Mokattam (Fig. 7), but tested it in Fayum before it was published (see Figs. 16 and 17). Blanckenhorn (1900, p. 430) contradicted Fourtau's description of building stone as a local facies, reporting it from many localities in addition to Gebel Mokattam, and he contradicted Fourtau's interpretation of building stone as an estuarine facies, arguing instead that it must represent a more open pelagic marine facies. Blanckenhorn returned to Fayum with Ernst Stromer von Reichenbach in January, 1902, as part of an expedition to collect vertebrate fossils (Stromer, 1903a). Blanckenhorn (1903) described "middle Eocene" stratigraphic sections from Gebel Mokattam, Gebel Ahmar, and Gebel Kibli el-Ahram in the vicinity of Cairo. Blanckenhorn was particularly interested in the transition from lower to upper Mokattam and this shows in his Gebel Mokattam section (Figure 7). Blanckenhorn omitted zones 1-1 and 1-2, what are today called the Lower Building Stone and Gizehensis members, to focus on the sequence from 1-3 (Upper Building Stone) through II-8 (Ain Musa bed). Important markers are the tafla in zone 11-1, abundance of nummulites through 11-1 and 11-2, appearance of Carolia placunoides in II-3, abundance of Plicatula in 11-4, Tunitella-rich "hard beds" and bone beds in 11-5 (few at Gebel Mokattam, but numerous in Fayum), hard ledge-forming sandy limestone or Carolia limestone in 11-6, variegated clays in II-7, and
Geolo ical
Gebel Mokattam (Cairo)
Survey
07 Egypt
Ain Musa Bed
Sandstone Marl
Shelly limestone Shale Shelly sandstone with Carolia Shelly limestone with plicatu~a Wadi Garawi Marl Qurn Limestone with marl, lowest Nummulites beaumonti
MAADl FM.
Fm. Fm,
Limestone with shale Limestone Limestone with shale
Observatory Fm,
GIUSHI FM.
Limestone with N. aff. pulchellus ('Operculinapyramidurn') Limestone
- - - -
Nodular limestone Limestone with burrows Limestone, last appearance of Nummulites gizehensis
I I
Limestone
'
UPPER BUILDING STONE MBR.
9
3
E
9
'-GIZTHETSIS
0
- -MBR,
Limestone with nummulites, esp. Nummulites gizehensis Limestone Limestone with nummulites Limestone
Mokattam Fm. I
I
LOWER BUILDING STONE MBR.
Strougo (1985a,b, 1988, in Said, 1990, fig. 24.4)
FIG. 4-Modern description and interpretationof Eocene stratigraphic section at Gebel Mokattam, based on thicknesses in Strougo (1985a,b, 1986), as illustrated in Said (1990, fig. 24.4). Vertical scale is the same as Fig. 5, but half that in subsequent figures. Lithologies are shown diagrammaticallyin left column and described in center. Strougo's (1988) correlationof Helwan formations and subdivisions of the Mokattamian Stage are also shown in center. Column at the right shows conventional stratigraphic subdivision into formations and members recognized by Geological Survey of Egypt (1983). Strougo (op. cit.) regarded the middle Mokattamian as Bartonian and upper Mokattamian as Priabonian, whereas Abdel-Kireem (1985) regarded much of the middle Mokattamian (including part of Giushi Fm.) as Priabonian. This and following localities are in Universal Transverse Mercator [UTM] grid zone 36R; kilometer coordinates of the locality within the grid zone are approximately 333.500E X 3323.000N.
limey sandstone or sandy limestone with Echinolampas crameri in 11-8 (Ain Musa bed). The section at Gebel Ahmar (now Gebel Akhdar under Nasr City) northwest of Gebel Mokattam is similar to that at Gebel Mokattam but thinner, with zones 11-1 and 11-2 being much condensed (Fig. 9). The transition from lower to upper Mokattam stage is preserved at Gebel Kibli el-Ahram in Giza (Fig. l o ) , where Blanckenhorn
interpreted zones as being of comparable thickness to those at Gebel Mokattam. Alternatively, it is possible that zones 1-2, 1-3, 1-4, 1-5 or 11-1 through 11-5 or 11-6 are missing and the uppermost bed here is 11-8 (it is a hard limey sandstone with Echinolampas crameri; Strougo's correlations, in Said, 1990, p. 461, suggest that zones 1-2 through 1-5 are missing along with the lower part of the upper Mokattam).
HISTORYOF STUDY: GEBEL MOKATTAM
Gebel Mokattam (Cairo)
Blanckenhorn
AAAo - Brown or light gray sandstone
Geolo ical Survey oQ~ g y p t Ain Musa Bed
AAAo - Iron-rich clay marl with gypsum AAAo - Variegated clay marl with Echinolampas AAAD - Fine-grained limey sandstone AAAD - Clay marl with Lucina
MAADl FM.
AAAT - Marl with Ostrea and Carolia AAAd - Gray shale with Ostrea and Carolia AAA1 -Yellow clay shale with beds of hard shelly ma1 AAA 1 [with Ostrea, Turritella, Carolia, Callianassa] AAA 1
7
AA - White limestone with bryozoans, large echinoids [Tafla at base w. sparry celest~tenodules]
-----
+ Eocetus schweinfurthi
GIUSHI FM.
Ala A l a - Soft chalky pure-white nummulitic limestone [White Buildi?g Stone of Cairo, with some celestlte, Cerithium, Lobocarcinus] A1 a
- - - -
UPPER BUILDING STONE MBR.
Ala
z- - - -
A1 b - Limestone with large nummulites
z $
A1 c - Limestone with large nummulites
GlZEHENSlS MBR.
E
A1 d - Limestone with large nummulites
0
++Eotheroides aegyptiacum Protocetus atavus, + Protosiren fraasi
A1 e - Nummulitic limestone with shark's teeth LOWER BUILDING STONE
A 2 - Compact white limestone with flint inclusions
Schweinfurth
FZG. 5-Eocene stratigraphic section at Gebel Mokattam based on thicknesses scaled from Schweinfurth's (1883) Plate XXI and descriptions in his text. Subdivisions from A2 through AAAa are system developed by Schweinfurth. Subdivisions from 1-1 through II-8 are parallel system developed by Blanckenhorn (1900, 1903). Column at the right shows formations and members recognized by Geological Survey of Egypt (1983). Note that vertical scale here is the same as Fig. 4 but half that in following figures. Diamonds mark probable levels where the type specimensof Eocetusschweinfurthi,Eothero&saegyptiacum, Protocetusatavus, and Protosiren fr- were found (according to Fraas, 1904a, pp. 200-201). UTM coordinates of the locality are approximately333.500E x 3323.000N.
Geolo ical Egypt Survey
Gebel Mokattam (Cairo)
07
Ain Musa Bed
A - Siliceous limestone B - Gray clays with gypsum C - Limestone with Ostrea, celestite inclusions D - Blue clays
MAADl FM.
E - Limestone with Ostrea elegans F - Limestone with Carolia placunoides
- - - - GIUSHI FM.
G - Limestone with Schizaster
---H - White limestone with Lobocarcinus, Cerithium UPPER BUILDING STONE MBR.
I - Limestone with Nautilus, Turritella
J - Limestone with Pycnodus, Echinolampas fraasi
- - - -
K - Ochrous limestone with shark teeth, N. gizehensis
Z GlZEHENSlS
o
Pz
MBR.
B
3
r-$---0
s
L - Yellow sandy limestone with Nummulites laevigatus
LOWER BUILDING STONE MBR.
M - Limestone with Rostellaria
N - Yellow limestone with Echinolampas africanus
Fourtau
FIG. 6-Stratigraphic section of Eocene at Gebel Mokattam, based on thicknesses scaled from Fourtau's (1897) figure 2 and descriptions in his text. Column at the right shows stratigraphic subdivision into formations and members recognized by Geological Survey of Egypt (1983). Fourtau's thicknesses are about one-half those of Schweinfurth (Fig. 3). Note that vertical scale here is double that in Figure 3. UTM coordinates of the locality are approximately 333.500E x 3323.000N.
Gebel Mokattam (Cairo) Fine-grained limey sandstone, Echinolampas crameri Variegated clays with gypsum, sand
11-8 -
Geolo ical Survey of Egypt Ain Musa Bed
11-7
Yellow and green clays
-
Hard yellow sandy bed Overhanging bed with endocasts, incl. many of Plicatula Two beds of dense yellow sandstone Numerous bivalves including Carolia, some bones
11-6 11-4 11-3
Yellow-white limestone with Nummulites beaumonti
-
MAADl FM.
11-2
Yellow and gray marl with gypsum
11-1
-
Variegated hard clay (trrf!a!with ce!es?i?s
---
Four soft limestones, small nummulites, Ostrea, Lucina
Limestone with Echinolampas fraasi
GIUSHI FM.
Yellow calcareous shale Nummulitic limestone with small nummulites Weathered limestone with Schizaster Calcareous shale 1-4 Limestone with Schizaster africanus, Echinolampas fraasi UPPER
-
Covered
Soft building stone, Lobocarcinus, Carcharodon
MBR.
1-3
Blanckenhorn (1 903)
---
FIG. 7-Stratigraphic section of Eocene at Gebel Mokattam, based on thickness and descriptions published by Blanckenhorn (1903, p. 370). Column at the right shows stratigraphic subdivision into formations and members recognized by Geological Survey of Egypt (1983). UTM coordinates of the locality are approximately 333.500E X 3323.000N.
Barron T. Barron's (1907) study, published posthumously, is important because he focused on a bed, the Ain Musa bed mentioned above (Blanckenhorn's bed 11-8, uppermost member of Maadi Formation at Gebel Mokattam), that can be traced from Gebel Mokattam across the Eastern Desert to the Gulf of Suez. On the north side of Gebel Mokattam this bed is overlain by red sands of the Gebel Ahmar Formation (Schweinfurth, 1883), while at Gebel Awebed 80 km east of Gebel Mokattam these beds are separated by 70 m of upper Mokattam marine deposits (Barron, 1907). At Gebel Anqabia, 25 km east of Gebel Mokattam, the Ain Musa bed and the Ahmar Formation are separated by 65 m of Ostrea and Caroliarich marine limestones and shales of the Anqabia Formation (Shukri and Akmal, 1953). Barron (1907, p. 87-92)
inferred that 70 m of marine upper Mokattam was removed by erosion before deposition of the Ahmar Formation, meaning that a major unconformity separates the Oligocene Gebel Ahmar Formation from the Eocene upper Mokattam (Maadi Formation). As illustrated below, this is important for understanding the stratigraphy and age of these deposits. Krasheninnikov and Ponikarov V. A. Krasheninnikov and V. P. Ponikarov (1965) were the first to study planktonic foraminifera from Gebel Mokattam. Two zones were recognized. The first, the Truncorotaloides rohri zone of latest middle Eocene age (now Paleogene planktonic foraminifera1 zone P14, Bartonian), included the Gizehensis and Upper Building Stone members. The second, the Globigerina
Wadi el-Sheikh (Eastern Desert)
Rough yellow-gray limestone
Alternation of white nodule-rich limestones and yellow or gray gypsiferous m a r k
Limestone, w i t h flint beds, nummulites, Zeuglodon teeth
Variegated gypsiferous clay and marl, Nummulites gizehensis
Gray limestone or glauconitic red-brown marl-limestone 1-1 Alternation of gypsiferous marl, limestone, variegated clay Blanckenhorn (1900)
FIG. 8-Stratigraphic section of Eocene at Wadi el-Sheikh in the Eastern Desert of Egypt, based on measurements and lithological descriptions of Blanckenhorn (1900). Blanckenhorn divided this section into five units, 1-1 through 1-5, and extended these zones to describe the lower Mokattam at Gebel Mokattam. Blanckenhornnoted that Nummulites gizehensis is found through this entire section (Blanckenhorn, 1903, p. 364) though interval 1-2 has the greatestconcentration (see Fig. 4). UTM coordinates of the locality are approximately 310.000E X 3175.000N.
corpulenta zone of late Eocene age (now P16, Priabonian), included the Giushi MemberIFormation and the Maadi Formation. Raising the Gizehensis and Upper
Building Stone members of the Mokattam Formation to latest middle Eocene (Bartonian) contradicted previous (and current) assessments, but Krasheninnikov and Poni-
HISTORY OF STUDY: GEBEL MOKA'ITAM
Gebel Ahmar (SW side) Sandstone with Vulsella, Carolia?, Cardita Debris, covered Yellow limey sandstone Sand, clay, and gyps~ferousmarl Limey sandstone with endocasts of Spondyhs, Cardita Yellow-brown sandy limestone, bivalve endocasts Dense yellow limestone Ochre-yellow nummulitic limestone over yellow tafla with celestite
11-1 -
White nummulitic limestone, small nummulites
1-5 Blanckenhorn (1 903)
FIG. 9-Stratigraphic section of Eocene on the southwest side of Gebel Ahmar 2-3 km northeast of Gebel Mokattam, based on measurementsand lithological descriptions of Blanckenhorn(l903, p. 373). Blanckenhorn divided the section into units 1-5 through 11-8 developed at Gebel Mokattam. If correctly correlated (note that diagnostic fossils characteristicof zones 11-6 and 11-8 are lacking), this section is much thinner than that at Gebel Mokattam (Fig. 7). UTM coordinates of the locality are approximately 335.500E x 3324.000N.
Gebel Kibli el-Ahram (Giza) Hard limey sandstone with Echinolampas crameri, Plicatula, Callianassa
11-4
Soft marl with mollusks including Plicatula, Turritella Gray Carolia bed with Ostrea clotbeyi, Plicatula Marl with gypsum, echinoids and mollusks
11-2
White and blue-gray clayey marl with fish bones, Lucina
11-1
White nummulitic limestone, Nummulites beaumonti, Echinolampas fraasi
1-5
Fourtau (1899). Blanckenhorn (1903)
FIG. 10-Stratigraphicsection of Eocene at Gebel Kibli el-Ahram east of the pyramid of Menkara or Mycerinus in Giza, based on measurements and lithological descriptions of Fourtau (1899) and Blanckenhorn (1903, p. 375). Blanckenhorn divided the section into units 1-5 through 11-4 developed at Gebel Mokattam (Fig. 7). Upper and lower Mokattam appear to be present, but more precise correlations are suspect. UTM coordinates of the locality are approximately 320.500E x 3317.000N.
karov's results corroborated a late Eocene age for the upper part of the Gebel Mokattam section. Strougo Amin Strougo (1976a) studied the Ain Musa bed at Gebel Mokattam and described temporal equivalents elsewhere. Strougo (1976b) documented a hiatus, with beds between the Plicatula bed and Ain Musa bed of the Maadi Formation missing east of Kait Bey on the northwest side of Gebel Mokattam. He attributed this 20 m discontinuity to local syndepositional tectonic movements. Strougo (1979; see also Strougo et al., 1982; Strougo and Boukhary, 1987) regarded the upper Mokattam as Priabonian (late Eocene), citing Carolia
placunoides as evidence, while including the whole middle Mokattam (possibly including Maadi Formation beds below those bearing Carolia placunoides) in the Bartonian (Biamtzian, middle Eocene). Strougo et al. (1982) described a section at Darb el-Fayum in Giza where the middle Eocene ends with an erosion surface and is directly overlain by a Carolia placunoides bed marking the beginning of the late Eocene. Strougo's synthesis of the stratigraphy and macroinvertebrate biostratigraphy of Gebel Mokattam and surrounding areas is the most comprehensive available (Strougo, 1985a,b, 1988; also Strougo in Said, 1990, fig. 24.4). Strougo extended stratigraphic nomenclature developed by Farag and Ismail (1955, 1959) to Gebel
Mokattam (Fig. 4), substituting this for the Mokattam, Giushi, Maadi sequence of Said (1962) and of Awad and Said (1966). Strougo (1988) interpreted molluscan stratigraphy to favor a middle-to-late Eocene boundary between the middle and late Mokattamian at the base of the Wadi Hof Formation.
eral review of Eocene stratigraphy in Egypt. A very useful map with accompanying text was published by the Geological Survey of Egypt (1983). Hassaan et al. (1990) compared microfacies at Kait Bey and Basateen on the northwest and southeast sides of Gebel Mokattam.
Abdel-Kireem M. R. Abdel-Kireem (1985) made a second study of planktonic foraminifera at Gebel Mokattam, following up on the work of Krasheninnikov and Ponikarov. AbdelKireem recognized three biostratigraphic zones: (1) the late middle Eocene Truncorotaloides rohn'zone [PI41 for the Gizehensis and Upper Building Stone members of the Mokattam Formation and for part of the Giushi Formation, (2) the earliest late Eocene Globigerinatheka semiinvoluta zone [PIS] for the upper Giushi and lower Maadi formations, and (3) the late Eocene Globigerina corpulenta zone [PI61 for the middle and upper Maadi Formation. Abdel-Kireem regarded Carolia placunoides as a facies fossil rather than an index to the Priabonian. He regarded the Giushi Formation as entirely synchronous with the Gehannam marl member (Ismail and Abdel-Kireem, 1975) of the Gehannam Formation. Both units were considered to straddle the middle-late Eocene boundary. Strougo and Boukhary (1987) responded by citing nummulite and calcareous nannofossil evidence indicating that the Gizehensis and Upper Building Stone members must be older than the Truncorotaloides rohri zone [P14], and they questioned whether any of the Giushi Formation could be late Eocene.
summary
Other authors Cuvillier (1930) provided several stratigraphic sections of Gebel Mokattam, interpreted in the context of a gen-
The Gebel Mokattam stratigraphic section includes three or six Eocene formations, depending on nomenclature employed (Fig. 4). The Mokattam and Gebel Hof formations are middle Eocene in age (Lutetian), and were deposited on a shallowing marine shelf. The Giushi Formation equivalent to the upper Observatory Formation has concentrations of celestite, was deposited in shallow marine waters, and may straddle the middlelate Eocene boundary (being mainly Bartonian but also, possibly, in part Priabonian). The Qurn, Wadi Garawi, and Wadi Hof formations, also called the Maadi Group or Maadi Formation, are middle to late Eocene in age (mainly Priabonian), and these were deposited in shallow nearshore to lagoonal marine environments. Mollusks favor a middle-to-late Eocene boundary between the middle and late Mokattamian (at the base of the Wadi Hof Formation; Strougo, 1988). Planktonic foraminifera favor a middle-to-late Eocene boundary within the middle Mokattamian and within the Giushi Formation (AbdelKireem, 1985). No significant unconformities have been identified within the Giushi Formation, but abundant celestite may indicate a low sea stand. There is an unconformity between the middle and late Eocene at Darb el-Fayum in Giza. Late Eocene marine Maadi and Wadi Hof formations are separated from overlying Oligocene continental beds of the Gebel Ahmar Formation by a major unconformity.
HISTORY OF STUDY: FAYUM The Fayum, like Gebel Mokattam, has a long and complex history of study, with early authors establishing the basic stratigraphic framework. Topography is importrrnt fclr ~nderstrrndingthis frzme~orkz ~ i?s d dwe!~pment . The cultivated oasis and lake Birket Qarun together occupy a broad valley floor dipping slightly to the northwest (NNW). A prominent escarpment, the Birket Qamn escarpment, rises above the northwest side of the lake (Fig. 2). This escarpment trends WSW-ENE and its top forms a broad plain, the plain of Dimeh, some 5-8 km wide. Strata exposed in the Birket Qamn escarpment were the basis for Schweinfurth's (1886) "zweite Stufe" and Beadnell's (1901) "Birket el Qurun Series" discussed in following sections of this chapter. Lithologically, the top of the first escarpment and all of the plain of Dimeh above it belong to the Qasr el-Sagha Formation. A second parallel escarpment, the Qasr el-Sagha escarpment, rises above the plain of Dimeh, and the top of the second escarpment forms a second narrower plain 4-5 km wide. Strata exposed in the Qasr el-Sagha escarpment were the basis for Schweinfurth's "dritten Stufett or "dritten Fayumstufe" and Beadnell's "Qasr el Sagha Series." Much of the second or narrow plain is Gebel Qatrani Formation. A third parallel escarpment, the Gebel Qatrani escarpment with basalt flows, rises above the second plain, and a third high plain dips gently away to the northwest for a great distance. Strata exposed in the Gebel Qatrani escarpment were the basis for Schweinfurth's "vierten Fayumstufe" and Beadnell's "fluvio-marine series" or "Jebel el Qatrani beds" (now Gebel Qatrani Formation). The third or highest plain is now usually placed in the Miocene Khashab Formation. The topography of northern Fayum is clearly stratigraphically controlled, but, as we shall see, the topography is not itself the stratigraphy. Study of Fayum stratigraphy developed in parallel with investigation of Gebel Mokattam, and these developments are summarized by author in the following pages. Schweinzrth Georg Schweinfurth made several visits to Fayum during and after his work at Gebel Mokattam. He
travelled to Wadi Muela in western Fayum in 1876, and he visited the island of Geziret el-Qarn in Birket Qarun in 1879. Schweinfurth found vertebrae of Eocene ~ h d e s t,a t h of sdachizm, 2nd remaim of ot5er fishes on the latter trip. These discoveries were described by Dames (1883a,b, 1894). Schweinfurth worked north of Birket Qarun in 1884, which may be the year he discovered the ancient stone building or "qmr"now known as Qasr el-Sagha (also called "Schweinfurth's Temple"). Exploration of Zittel's "geologisch unbekanntes Gebiet" came in January 1886 when Schweinfurth made a monthlong traverse of the western and northern deserts of the Fayum depression. His report (Schweinfurth, 1886) included a good topographic map of Fayum. The expedition started near Qalamsha and travelled in a large circle through the desert first southwest to Wadi Muela, then northwest to Wadi Rayan and Minqar el-Rayan (Schweinfurth' s " Cap Rajan") , and then farther northwest to Garet Gehamam (Schweinfurth's "Haram Meduret el-Barhl") . Eocene invertebrates were found all along the traverse. Schweinfurth clearly wanted to explore valleys and escarpments visible in the desert west of Garet Gehannam, but wrote that he was deterred by poor camels and assistants he did not trust. To the west are Minqar elHut and Wadi Hitan (Zeuglodon Valley) where hundreds of archaeocete cetacean skeletons lie exposed at the surface over a large area of desert. Unaware of these and unable to proceed westward, Schweinfurth turned northeast toward Birket Qarun. Teeth of a sawtooth shark were found west of the lake (the type of Amblypristis cheops described by Dames, 1888). Remaining days of the expedition were spent exploring north of Birket Qarun where Schweinfurth found one good dentary of an archaeocete (the type of Zeuglodon osiris described by Dames, 1894). Schweinfurth's (1886) description of the geological section north of Birket Qarun is confusing and disappointing, especially in comparison to the clear geological sections and maps he prepared for his Gebel Mokattam study. Schweinfurth divided Fayum strata into four "stages" (Stufe) or intervals, corresponding to successive escarpments above Birket Qarun. For simplicity these can be referred to as I (basal interval near the lake), II
Tamariskenbucht Yellow marly limestone Cla marly limestone with bivalve remains
elr row
Gray-green clay with gypsum
11-7
Gypsiferous clay and green sand Limestone oyster bank with Ostrea elegans, Carolia, Vulsella Gray and green clays and marl
ll-5b
-
Terrace with Ostrea Marl with silicified wood Limestone terrace with Ostrea elegans, Ostrea cloti Limestone terrace with Carolia and Ostrea Clay shale with plant remains, fish skulls, marine mammal vertebrae Terrace with Ostrea cloti, Turritella
ll-5a
Covered Blanckenhorn (1903)
FIG. 11-Stratigraphic section of Eocene at Tamariskenbucht about 12-15 km (half-day's travel) NNE of the temple building at Qasr el-Sagha, based on measurements and lithological descriptions of Blanckenhorn(l903, p. 381). Blanckenhorn divided the section into units 1'-5a through 11-8 developed at Gebel Mokattam (Fig. 7). UTM coordinates of the locality are approximately 284.000E x 3289.000N.
Gebel Achdar Yellow-white limestone with Echinolampas crameri 11-7
Gray-green clay with veins of fibrous gypsum
White Carolia limestone Dark clay, one bone White sandstone Sandstone with fish bones, Pristis, Myliobates, Otodus Three terraces with Ostrea elegans and Turritella Marl shale, Moeriophis snake vertebrae, turtle shell, crocodilian bone Yellow-red crumbly marl White sandstone or clay, fish bones, Zeuglodon. Moeritherium
ll-5a
Blanckenhorn (1903)
FIG. 12-Stratigraphic section of Eocene at Gebel Achdar about 6 km (1.5 hours) NNE of the temple building at Qasr el-Sagha, based on measurements and lithological descriptions of Blanckenhorn (1903, p. 382). Blanckenhorn divided the section into units 11-5a through 11-8 developed at Gebel Mokattam (Fig. 7). UTM coordinates of the locality are approximately 279.500E X 3281.000N.
(Birket Qarun escarpment), I11 (Qasr el-Sagha escarpment), and IV (Gebel Qatrani escarpment). Schweinfurth's stages are simple enough, but these are numbered inconsistently in his text. He gave thicknesses for each interval, but some were reported in terms of elevation above lake level while others were reported relative to their elevation above sea level (Birket Qarun lake level is about 40 m below sea level). Schweinfurth's thicknesses, as reported, are much less than thicknesses determined by subsequent investigators. Thus I think
Schweinfurth may have meant to call the 40 m interval from lake level to sea level his first interval, the next 60 m his second interval, the next 90 m his third interval, and a final 160 m his fourth interval. These values are at least roughly proportional to measurements reported by later authors. Schweinfurth (1886, p. 135) first described the lowest interval as including a conspicuous red shell bed and being capped by an oyster conglomerate. Later @. 136) he described the first unit as unfossiliferous gray and
HISTORYOF STUDY: FAYUM
-- Klippenecke E
In U)
a~ C
Yo
5
10
4
L
fi
0
Oyster bed with Ostrea cloti Light yellow and gray marl
ll-5a
White sand Limestone with violet nodules, Gisortia gigantea, some Carolia, vertebrae Turritella bed with Ostrea Intermediate beds, covered Oyster bed with Ostrea elegans
11-4
Blanckenhorn (1 903)
FIG. 13-Stratigraphic section of Eocene at Klippenecke about 2 km (0.5 hours) NNE of the temple building at Qasr el-Sagha, based on measurements and lithological descriptions of Blanckenhorn(l903, p. 383). This section must have been measured very near the Wadi Efreet section of Bown and Kraus (1988; Fig. 31). Blanckenhorn divided the section into units 11-4 through 11-5a developed at Gebel Mokattam (Fig. 7). UTM coordinates of the locality are approximately 277.000E x 3278.000N.
Qasr el-Sagha Gypsiferous marl Hard yellow marl Gypsiferous marl with fish bones Limestone with oysters Limestone with Carolia, Turritella
Yellow sand with crossbedding, rare corals, turtle remains
Bench with Carolia Ostrea Turritella Red bed with bone'over larhinated clay Turritella bench overlying terrace with molluscan endocasts Marl Hard oyster bank Bench with Turritella overlying Carolia White bench with fish otoliths and teeth Marl with marine mammal vertebrae Bench with solitary corals, Turritella, etc. Yellow marl Marl, some Carolia, large bones near base Bench with Kerunia ('Hydractinia'1, Ostrea, Plicatula, Carolia, etc. Bench with Ostrea cloti, Callianassa (temple stands on this bench) Blanckenhorn (1 903)
FIG. 14--Stratigraphic section of Eocene immediately behind the temple building at Qasr el-Sagha, based on measurements and lithological descriptions of Blanckenhorn (1903, p. 384). Blanckenhorn divided the section into units 11-3 through 11-7 developed at Gebel Mokattam (Fig. 7). UTM coordinates of the locality are approximately 274.800E x 3276.500N.
ash-gray marls overlain by fossiliferous beds with Ostrea clotbeyi, Carolia placunoides, etc., capped by a conspicuous hard oyster bank more than a meter thick. From context @. 137), and my own knowledge of the stratigraphy, it appears that only the unfossiliferous gray and ashgray marls are in interval I, and the rest of the section is in interval II. Schweinfurth mentioned chalk-white mollusk shells in a sandy ocherous yellow or dark bloodred clay in this interval, and a "best" fossiliferous locality 3 km west of the west end of the lake (Beadnell, 1905, p. 46, included this bed in the upper part of his
Birket Qarun Series). Schweinfurth considered this interval to be the same as that producing the mollusks he collected in 1879 on Geziret el-Qarn, described and identified as "upper Parisian" by Mayer-Eymar (1883). Schweinfurth regarded the upper part of Fayum interval 11as equivalent to part of his interval AAA1, the lowest upper Mokattam stage at Gebel Mokattam. Schweinfurth (1886) started a paragraph on p. 138 by mentioning the "zweite Stufe," but it seems clear that this and subsequent paragraphs are actually about his third interval. Schweinfurth regarded the escarpment by the
Gebel Hameier Carolia limestone
Ash-gray clay shale with plant remains
Brown sandstone Clay shale psum. slabs auconltlc sand with red ironstone Terrace with Ostrea reili, Lucina, Turritella Bed w ~ t hTurr~tella,Ostrea elegans
8'
Yellow brown marl. some bone Yellow ar b d w't Ostr a cloti an Tur itella over 9art cray skae w~t%bones t$cadsh etc. Yellow marl overl~lngoyster bed w ~ t hmany Ostrea cloti Yellow hard bed with Turritella Dark gray clay shale Oyster bed with Ostrea cloti, numerous Turritella Covered, oyster bed in middle White sand Blackish clay shale Compact limestone with Carolia, Macrosolen, etc. Shaly marl Limestone with Ostrea and Turritella overlying Carolia Light gray marl Yellow-gray shaly marl with head-sized concretions Terrace with Ostrea, Carolia, Turritella, Callianassa Gray and yellow marl Oyster bed with Kerunia ('Hydractinia 'I, Turritella Gray and black clay shale 11-3 Oyster bed with Kerunia ('Hydractinia'),large Ostrea fraasi Marl Oyster bed with small oysters
Blanckenhorn (1903)
FIG. 15-Stratigraphic section of Eocene at Gebel Hameier about 6 km (1.5 hours) WSW from the temple building at Qasr el-Sagha, based on measurements and lithological descriptions of Blanckenhorn(1903, p. 386). This section appears to have been measured a kilometer or so east of Blanckenhorn'sKorallenhiigel section (Fig. 16). Blanckenhorndivided the section into units 11-3 through 11-6 developed at Gebel Mokattam (Fig. 7). UTM coordinates of the locality are approximately270.500E X 3275.500N.
alten Tempel [Qasr el-Sagha] as a characteristic example of interval 111, and further divided it into twenty subunits. He correlated the whole with beds AAAl through AAAa at Gebel Mokattam. Most interesting from our point of view was discovery of a lower jaw of "Zeuglodon"with five teeth, and also two associated lower jaws of "Schwein oder Tapir erinnernden Geschopfes" [pig or tapir-like creatures] at a locality in interval 111. The former specimen is the holotype of Zeuglodon osiris described by Dames (1894). The latter specimen was never identified or illustrated, but Schweinfurth's comparison to a pig or tapir suggests that it was Eosiren or Moeritherium. Schweinfurth (1886, p. 139) described the locality as follows:
An dem von mir 12% krn im Westen vom alten Tempelbau ausgebeuteten Berge (wie benennt man solche unbekannte Grossen?), der als Vorwerk der Abfalkrlinie der dritten Stufe ein isoliertes Stuck derselben ausmacht, d m sich von allen Seiten um so bequemer untersuchen liess, machte ich in derselben Schicht zwei wichtige Knochenfunde.
the hills (how does one refer to such unnamed masses?) 12% km west of the old temple, which constitute an isolated parcel in the foreground of the thirdstage scarp, easily located from all sides, I made two important finds of bones in the same bed.] These hills at the front of the Qasr el-Sagha escarpment must have been near Garet el-Esh (flat-topped "hill of the
Korallenhiige!I Yellow-gray limestone with Echinolampas crameri, Turritella Gray and yellow clay w i t h gypsum Marly sand with glauconite, bones
Variegated gypsiferous clay Blocky limestone ashlar with oysters White limestone with Carolia, Plicatula Light gray sand and clay Ash-gray clay shale, white sand, brown sandstone Red-violet sandy limestone with oysters Variegated marl with gypsum fl'ecks Oyster bed Red shale with white mollusk shells Yellow Turritella bed White sandstone, cross-bedded Wall with Ostrea, Carolia Gray-green clay w i t h gypsum, large Carolia shells in middle
Marl shale Marl shalewith Plicatula, Ostrea, Carolia, Turritella Yellow shale with bed of Carolia in upper part Marl shale with Ostrea cloti in upper part Yellow and blue marl crowned by bed with Carolia Yellow marl, Kerunia ('Hydractinia'),Ostrea cloti Calcareous shale, including reef with 'Astrohelia', Ostrea fraasi BIanc
FIG. 16-Stratigraphic section of Eocene at Korallenhiigel7 km northwest of Dimeh in Fayum, based on measurements and lithological descriptions of Blanckenhorn (1900, p. 448; 1903, p. 388). Blanckenhorn first divided the section into units II-1 and 11-3 through 11-8. Later he included beds referred to 11-1 in II-3 and subdivided 11-5 into two parts. These are the same zones of the upper Mokattam that Blanckenhornrecognized at Gebel Mokattam (Figs. 5 and 7). UTM coordinatesof this locality are approximately 269.000E X 3274.000N.
nest"), which is shown as being 12 km west of the Qasr el-Sagha temple on Beadnell's (1905) geological map of the Fayum depression. "Zeuglodon" osiris, Eosiren, and Moeritherium are all found at this place. The calcareous shales [Mergeln] yielding the Zeuglodon osiris type at the ?-I3erge are overlain by beds with Ovula, Strombus, Solen, and Nautilus that Schweinfurth (p. 140) correlated with his AAA/3 interval at Gebel Mokattam. Many bivalves here are preserved as compact masses of leather-brown colored steinkerns, overlain by Carolia and Ostrea clotbeyi. The top of the cliffs behind the Qasr el-Sagha temple building are capped by a 2 m light brown, dense, hard, calcareous sandstone packed with shell casts and serving as the top of a conspicuous 15 m cliff of gray marl shale (walls of the Qasr el-Sagha temple building were constructed from fallen pieces of the calcareous sandstone).
According to Schweinfurth (p. 140), the whole Qasr elSagha escarpment sequence (interval III) ends with yellow gypsum-rich shales with Carolia, EchinoEampas c r m r i , Micropsis, and every widely distributed species of upper Eocene oyster in Egypt, capped by an irregular hard white limestone [Kalkbreccie]. This "Kalkbreccie" forms a hard plateau surface 1% km wide. Heat and haste prevented Schweinfurth from making a thorough study of the rest of the second plain and the Gebel Qatrani escarpment (interval IV), but he was able to report brightly colored white, ocher-yellow, and brickred shales and sandstones like those at Gebel Ahmar near Gebel Mokattam, and wood of fossil forests like those known from the vicinity of Cairo. Schweinfurth recognized that fossil forests in interval IV meant retreat of the sea between interval III time and interval IV time.
Kamelpass Yellow-white limestone with Echinolampas crameri, Callianassa
-
White, ochre-yellow, and gray calcareous shale, clay with gypsum
Reddish glauconitic sand Dark green glauconitic sand and black clay, some gypsum Red-gray porous limestone with Ostrea, Cardium Crumbly limestone with Carolia, Ostrea, Turritella Carolia bed Dark gray and yellow clay and sandy calcareous shale with gypsum Black carbonaceous shale, paper shale Light gray and black gypsiferous sandstone with nodules Calcareous sandstone with oysters Limestone with Turritella Calcareous shale Turritella bed Clay Ostrea clotbeyi bed Gypsiferous clay with a Carolia bed Carolia bed with giant Carolia shells
11-4
Gypsiferous clay with red and brown streaks Plicatula spp., Ostrea clotbeyi
Blanckenhorn (1900)
FIG. 17-Stratigraphic section of Eocene at Kamelpass about 9-10 km northwest of Dimeh in Fayum, based on measurements and lithological descriptions of Blanckenhorn (1900, p. 449). Blanckenhorndivided the section into units II-4 through 11-8. These are the same zones of the upper Mokattam that Blanckenhorn recognized at Gebel Mokattam (Figs. 5 and 7). UTM coordinates of this locality are approximately 267.000E X 3276.000N.
Mayer-Eymar Karl Mayer-Eymar's first work on Egyptian faunas was a study of invertebrate fossils from Geziret el-Qarn in the Fayum. These were collected by Schweinfurth in 1879, and published by Mayer-Eymar (1883) as a part of Zittel's Betriige zur Geologie und Palaeontologie der Libyschen Wiiste. Mayer-Eymar's first visit to Egypt, discussed above, was brief and limited to the vicinity of Cairo (Mayer-Eymar, 1886). Mayer-Eymar's study of the Fayum started with a paper interpreting Schweinfurth's 1886 observations (Mayer-Eymar, 1893). He made a two-day excursion to Fayum in 1894, when he worked north of Dimeh. The report on this was entitled " Quelques mots ..." (Mayer-Eymar , 1895). True to the title, it was brief. Observations on the "Ligurian" [Priabonian, late Eocene] were very limited, and MayerEymar's sole conclusion was that there was evidence of a late Eocene sea in Fayum. Mayer-Eymar observed the "Tongrian" [Lattorfian or Rupelian, early Oligocene] fossil forests and basalt, attributing discovery of these to
Schweinfurth. The following year, in 1895, MayerEymar made a 7-day trek from Fayum to Kom Aushim, to Dimeh, then northward to climb the Fayum escarpments, and finally eastward to return to Cairo (MayerEymar, 1896). Observations on both of these trips were made haphazardly, with little documentation of distance or thickness, and they consequently retain little value. Further, Mayer-Eymar appears to have had a poor sense of direction, and it is disconcerting to read that Dimeh is west of Birket Qarun (it is north of the lake) or that Mayer-Eymar thought he worked 4 km south of the Qasr el-Sagha section studied by Schweinfurth (1886) when he must have worked 4 km west of it.
Blanckenhorn Max Blanckenhorn's (1900) discussion of Gebel Mokattam is reviewed above. He also published two Fayum stratigraphic sections of the uppermost marine Eocene " Carolia-Stufe" in his 1900 paper. The sections are shown graphically in Figures 16 and 17.
Zeuglodonberg White Carolia limestone with Ostrea
Ash-gray clay, shale, brown sandstone, mammalian vertebrae
Oyster bank with Ostrea overlying Carolia Limestone w ~ t hmany Turritella Light gray and yellow marl with white gypsum flecks Dark clay shale with gypsum, sawfish, bony fish, turtles Violet Turritella bed overlying Carolia bed, level of Zeuglodon zitteli type Gray clay w . violet nodules, wood, many bones of fish, snakes, etc. Yellow red Carolia marl with Eosiren skull over crossbedded white sandstone Gray clay and marl with bones Covered, contains Euspatangus, Plicatula Blanckenhorn
FIG. 18-Stratigraphic section of Eocene at "Zeuglodonberge"about 12% km west of Qasr elSagha (Schweinfurth, 1886, p. 139). Blanckenhorn(l903, p. 390, see Fig. 19) refers to this as a single hill, Zeuglodonberg (Fig. 19), 3 hours WSW of Qasr el-Sagha. In either case, this section must have been measured close to Garet el-Esh. Measurements and lithological descriptionsare from Blanckenhorn (1903, p. 390). Blanckenhorndivided the section into units 11-4 through 11-6 developed at Gebel Mokattam (Fig. 7). UTM coordinates of the locality are approximately 265.000E X 3274.000N. The first section was measured at a place Blanckenhorn acknowledged Mayer-Eymar for calling "Korallenhilgel" (possibly in conversation, because I have found no reference to this in Mayer-Eymar's published papers). Blanckenhorn adopted this name as well. According to Blanckenhorn (1900, p. 447), the hill is 5 % km on an exactly northwest bearing from the temple ruin at Dimeh. Later Blanckenhorn (1903, p. 388) indicated that Korallenhiigel is "2 Stunden" northwest of Dimeh. The latter, applying Zittel's Kamelstunden conversion factor, corresponds to a distance of about 7-9 km. A northwest bearing intersects the Qasr el-Sagha escarpment at a distance of just over 7 km [on the 1:100,000 Gebel Qatrani topographical map (Survey of Egypt, 1956)l. The second or "Kamelpass" section was measured farther to the northwest along a route Blanckenhorn (1900, p. 448) described as the only one by which camels can easily ascend the escarpment in the west. This pass is shown clearly on the Gebel Qatrani topographical map. The two localities lie 3-4 km east and northeast of Garet el-Esh (Fig. 2). Comparing the Korallenhiigel and Kamelpass sections, the boundaries between Blanckenhorn's zones 11-3and II4 and between his zones 11-4 and 11-5 appear arbitrary. By contrast, zone 11-6 is well defined as a prominent ledge-forming limestone sequence rich in Carolia, 11-7 is well defined as a thick section of sands and shales, and 11-8 is well defined as another prominent ledge and
plateau-forming limestone bearing the small echinoid Echinolampas crarneri. These are among the most widely traceable units in the Fayum Carolia beds. Blanckenhorn (1900) did not discuss Fayum formations underlying his Carolia beds, but noted (p. 452) that overlying "Bartonian" or "upper Eocene" strata could be divided into two stages, a lower stage of fresh and brackish water sediments, and a higher stage of predominantly marine sediments alternating with fresh water beds up to the capping basalt. As noted above, Blanckenhorn returned to Fayum with Ernst Stromer von Reichenbach in January, 1902, as part of a vertebrate paleontological expedition (Stromer, 1903a). The Stromer expedition of 1902 made two traverses through Fayum beds west and north of Birket Qarun (Stromer, 1903a, p. 342). The first traverse took eleven days (January 17-27) and went from the temple ruin at Qasr Qarun west and north around the west end of Birket Qarun, then east on the north side of the lake to Dimeh and Qasr el-Sagha, and then to Tamia in the Fayum oasis. The second traverse took thirteen days (February 6-18) and went directly overland from Cairo to the northern Fayum, providing access to bone beds of the "upper Eocene" not reached from below. This trek also ended at Tamia. Stromer and Blanckenhorn made a trip to Wadi Natrun, looked for fossils and measured sections in Wadi Ramliya southeast of Wasta in the Eastern Desert, and then
FIG. 19-Sketch of "Zeuglodonberg" locality as shown in figure 12a of Blanckenhorn (1903, p. 391). Note developmentof ridges correspondingto fossil-rich "harte Bank" or hard bed deposits at top of zone 11-4 and within 11-5a. This locality is within the Zeuglodonberge hills of Schweinfurth (1886, p. 139), type locality of Saghacetuc; osiris (Dames 1894), and must be somewhere near Garet el-Esh. Numerals 4, 5a, Sb, and 6 refer to zones 11-4, 11-Sa, II-5b, and 11-6, respectively. T2 and T3 label Tunitella-rich horizons. Z is interval with Zeuglodon, and individual finds are marked with an x.
Zeuglodonberg NW Carolia limestone
Black clay shale, white sandstone, gypsiferous clay Clay, limestone, and yellow marl Gray clay Light yellow sandy marl Gray clay interbedded w i t h white sand T w o iron-mottled fish bonebeds, Hemipristis, etc. Black clay Yellow sandy marl Red Zeu lodon bed with Carolia Turritella Marl wit# sirenian skeleton overjying Carolia, Turritella Gypsiferous clay
Blanckenhorn (1 903)
FIG. 20-Stratigraphic section of Eocene at Zeuglodonberg NW about 1.5 km (0.5 hours) northwest of Zeuglodonberge, based on measurements and lithological descriptions of Blanckenhorn (1903, p. 392). Blanckenhorn divided the section into units 11-4 through II-6 developed at Gebel Mokattam (Fig. 7). UTM coordinates of the locality are approximately 263.200E X 3274.000N.
accompanied Schweinfurth to Qena and Luxor. Stromer (1903a) expressed some disappointment in the paleontological results of his expedition, attributing poor collecting to the fact that the fossiliferous beds had already been examined by others, but he also took some satisfaction from Blanckenhorn's geological observations.
Stromer (1903a) was able to describe one new skull of Zeuglodon osiris (now Saghacetus osiris). Blanckenhorn's (1903) report following the Stromer expedition covered a wide range of geological problems in Egypt, with parts of the report devoted to the boundary between the Cretaceous and Eocene, to the Mokat-
Garet el-Naqb Carolia bed with Ostrea and Turritella White marl with brown ironstone overlying Carolia Green clay Bed of Turritella overlying Carolia Green sandy marl with gypsum Bed of Carolia and Ostrea Gray-green and blackish clay Yellow marl, red nodules, white mollusk shells Blackish sandy clay with veins of white gypsum Yellow-g:ay marl, red-0:own nodules, white mollusk shells Gray-brown or black marl with white gypsum stringers
Steep precipice of yellow marly sandstone
Covered, some with superficial diluvial lake sediments
Blanckenhorn (1903)
FIG. 21-Stratigraphic section of Eocene at Garet el-Naqb just north of the west end of Birket Qarun (X on Schweinfurth's, 1886, map; Gebel d7Archaic of Mayer-Eymar), based on measurements and lithological descriptions of Blanckenhorn (1903, p. 393). Blanckenhorn divided the section into units 11-5a through 11-6 developed at Gebel Mokattam (Fig. 7),but this interpretationis certainly in error. Blanckenhorn's "steepprecipice of yellow marly sandstone" is Birket Qarun Formation as this formation is understood here. Overlying beds belong to the lower part of the Qasr el-Sagha Formation and are probably older than Blanckenhorn's zone 11-1 at Gebel Mokattam. UTM coordinates of the locality are approximately 247.500E x 3262.800N.
tamstufe or "middle Eocene," to the upper Eocene and Oligocene, and to basalt in the Libyan or Western Desert. The only part of the report that concerns us here is the section on the "middle Eocene." Blanckenhorn reviewed his earlier work on the Mokattam Eocene in which the lower Mokattam was divided into five units 1-1 through 1-5, and the upper Mokattam was divided into eight units 11-1 through 11-8. He reaffirmed that Gebel Mokattam is not the most representative section for either the lower or upper Mokattam. Advantages of the Wadi el-Sheikh section in the Eastern Desert over the lower Mokattam section at Gebel Mokattam are exposure in four distinct terraces instead of one cliff section, greater thickness, and richer fossil production (Blanckenhorn, 1903, p. 364). Advantages of the Fayum section
in the Western Desert over the upper Mokattam section at Gebel Mokattam are its three-fold greater thickness, richer fossil production, better fossil preservation, and greater accessibility. Blanckenhorn (1903) described ten "middle Eocene" stratigraphic sections from Fayum, and one from Wadi Ramliya in the Eastern Desert east of Fayum and Wasta. These are logically described from northeast to southwest, that is, from the northeastern Fayum to Wadi Ramliya to the southwest. Nine of Blanckenhorn's sections describe upper Mokattam beds along a 30 km length of the Qasr el-Sagha escarpment in northern Fayum. These are, from east to west: Tamariskenbucht (Fig. 1I), Gebel Achdar (Fig. 12), Klippenecke (Fig. 13), Qasr el-Sagha (Fig. 14), Gebel Hameier (Fig. 15),
Wadi Ramliya Friable limestone over brown limestone with Nummulites discorbina, Carolia Yellow marl with small nummulites 11-2 Yellow nummulitic limestone, Nummulites beaumonti Yellow marl shale Yellow nummulitic limestone Yellow marl with beds of yellow limestone, no nummulites
11-1 1-5
-
White calcareous shale White limestone Friable marly limestone Four limestone beds Covered, shale Yellow-white shaley marl
Blanckenhorn (1 903)
FIG. 22-Stratigraphic section of Eocene at Wadi Ramliya in the Eastern Desert east of Fayum, based on measurements and lithological descriptions of Blanckenhorn (1903, p. 367). Blanckenhorn divided the section into units 1-4 through 11-3 developed at Gebel Mokattam (Fig. 7),but this is questionablebecausethere is so little basis for comparisonin terms of fauna. This section is isolated from all others, and the locality should represent depositional environments much farther onshore. UTM coordinates of the locality are approximately338.000E x 3235.000N. Korallenhiigel (Fig. 16), Kamelpass (Fig. 17), Zeuglodonberg (Figs. 18, 19), and Zeuglodonberg NW (Fig. 20). The sections Blanckenhorn studied generally preserve his Gebel Mokattam zones 11-3 through 11-8. Lower beds are not exposed in the Qasr el-Sagha escarpment. Zones 11-6 and 11-8 both form prominent ledges and these are often separated by a wide terrace developed on the top of 11-6, which explains why some of Blanckenhorn's sections stop at 11-6. All of these sections are very similar, and there is considerable lithological continuity and uniformity in the zones. Prominent markers like 11-6 are easily traced from one section to the next. Within zones, especially 11-3 through 11-5 and 11-7, there is variability in facies representing local environments on a shelf floor influenced by factors like clastic influx and distribution. The thickest interval in Blanckenhorn's Fayum sections is usually 11-5, which is very different from the situation at Gebel Mokattam. 11-5 includes numerous benches labelled "harte Bank" [hard bed], and Blanckenhorn sometimes noted that these tend to have Carolia at the base and Turritella or Ostrea at the top. Fossils identified by Blanckenhorn are all marine except for occasional drifted wood and possibly some lower vertebrate remains, and Blanckenhorn interpreted the entire sequence as representing marine deposition. Blanckenhorn's (1903) last Fayum section, at Garet elNaqb (Fig. 21) is interesting because it was measured along a lower escarpment, the Birket Qarun escarpment, near the west end of lake Birket Qarun. The Garet elNaqb section spans a much lower stratigraphic interval,
but Blanckenhorn appears not to have realized this and erroneously identified the same sequence of zones 11-5 through 11-6 recognized elsewhere in Fayum. This mistake demonstrates the importance of lithological continuity andlor abundant faunas in well studied strata when making lateral correlations. Blanckenhorn's final section, at Wadi Ramliya east of Fayum (Fig. 22) is isolated from all the others, the section is relatively short, and it is southeast of the others and hence farther onshore, making interpretation difficult and questionable. Even the presence of Carolia at the top of a sequence of nummulite-rich limestones and shales is difficult to interpret because these sometimes occur together in the Wadi Rayan Formation as well as in the Qasr el-Sagha Formation (see below). Blanckenhorn (1903, p. 399) was the first to recognize an unconformity between the marine upper Eocene [Qasr el-Sagha Formation] and overlying "fluvio-marine" beds [Gebel Qatrani Formation] : Obwohl eine Diskordanz nicht direkt zu beobachten ist, kiinnte man doch speziell im NO. an eine Liicke oder Unterbrechnung der Sedimentation zu Beginn des Obereocans (Bartonien) denken und geneigt sein, den ganzen fluviomarinen Kompla ins Oligocan zu stellen.
[Although an unconformity cannot be observed directly, one can still recall, especially in the northeast, a gap or interruption of sedimentation at the beginning of the upper Eocene due to erosion, thus placing the whole Gebel Qatrani fluviomarine complex in the Oligocene].
HISTORY OF
STUDY: FAYUM Minqar el-Rayan
Hard snow-white limestone with Nummulites gizehensis, Ostrea, Lucina, Carolia
Wadi Rayan Fm. Sandy clays with Carolia, Ostrea, Nummulites
Green shelly sands with Nummulites gizehensis, N. curvispira, Ostrea Hard slate-blue shale, weathering to paper shale Limestone band of nummulites and echinoids
Sandy clays with Ostrea, Carolia, nummulites
Hard white marly limestone Shelly band rich in corals
Hard white nummulitic limestone full of Nummulites gizehensis
Beadnell (1 905)
FIG. 23-Stratigraphic section of Eocene at Minqar el-Rayan in the western Fayum depression, based on measurements and lithological descriptions of Beadnell (1905, p. 36). Beadnell included all of this section in his Wadi Rayan series (Wadi Rayan Formation), but it has subsequently been subdivided into Muela, Midawara, Sath el-Hadid, and Gharaq formations by Iskander (1943). UTM coordinates of the locality are approximately238.000E X 3223.000N.
This observation, communicated via Stromer (1907) and Osborn (1908), probably explains how the Gebel Qatrani Formation in Fayum came to be regarded as Oligocene in age. It has been called Oligocene by virtually all authors since Osborn (1908).
Blanckenhorn (1921) is a very useful review of the geology of Egypt as it was understood by early investigators. Much of the discussion of Fayum stratigraphy repeats work published earlier, but a new north-south cross section of the entire Fayum stratigraphic sequence
Garet Gehannarn Hard yellow and white limestone with Carolia, Ostrea fraasi, numerous nummulites
Qasr el-Sagha Fm. Limestone full of Turritella, Ostrea clotbeyi Brown clays Shelly limestone with Carolia, Ostrea, Turritella Greenish clays Nummulitic limestone, Carolia, Kerunia ('Oerunia'),Turritella Light blue clays Green and brown sandstone, irregular concretions Brown shelly limestone, Carolia, Ostrea spp., Turritella, nummulites
Yellow sandstone, nummulite bands, calcareous concretions near base
Birket Qarun Fm. Clays with much gypsum
Yellow sandstone, bands crowded with nummulites, some oysters
Yellow sandstone, nummulites, Cardita casts, small Ostrea
Ravine beds = Gehannarn Frn. Argillaceous sandstone with thick stockwork of gypsum Light yellow, brown gypseous clays Clayey limestone with fish scales, yellow-white marls Hard shelly limestone and marl
Ochreous-yellow, gray, and white clays and marls, much gypsum Hard yellow-white shaly marl Yellow marly clays, gypsum, Zeuglodon common BeadneH (1 905)
FIG. 24-Stratigraphicsection of Eocene at Garet Gehannam in the northwesternFayurn depression, based on measurementsand lithological descriptions of Beadnell, 1905, p. 38). Beadnell recognized three formations here: Ravine beds (Gehannam Formation, 70 m), Birket Qarun series (50 m), and Qasr el-Sagha series (45 m). Upper 24 m sandstone of Beadnell's Ravine beds is lithologically indistinguishable from overlying sandstones and is now included in the Birket Qarun Formation. *
West End of Birket Qarun Hard gray sandstone and shelly limestone, forms plain dipping t o north Impure sandstone w i t h numerous Kerunia, corals, Ostrea spp., Carolia, Plicatula Clays Argillaceous sandstone
Qasr el-Sagha Fm.
Clays
Earthy limestone crowded w i t h Ostrea, Plicatula, Turritella, etc. Thin-bedded clays, gypseous, sometimes carbonaceous Hard fossiliferous sandstone Gypseous clays Hard ferruginous sandstone w i t h nummulites, Operculina, Kerunia, Lucina, Natica Hard purplish clays Yellowish sandstone w i t h Ostrea, Lucina, Turritella Purple clays w i t h strings of gypsum
Light yellow sandstones, occasional concretionary beds
Birket Qarun Fm.
Gray and brown clays
Ravine beds = Gehannam Fm. Marls, shales, sandstones, and limestones
Beadnell (1905)
FIG. 25-Stratigraphic section of Eocene at west end of Birket Qarun in the northwestern Fayum depression (see Fig. 26), based on measurements and lithological descriptions of Beadnell (1905, p. 46). This is near Garet el-Naqb (compare section by Blanckenhorn in Fig. 21). Beadnell recognized three formations here: Ravine beds (Gehannam Formation, 45+ m), Birket Qarun series (50 m), and Qasr el-Sagha series (42+ m). Lower-18 m of gray and brown clays and upper 15 m of clays and thin sandstones of Beadnell's Ravine beds are lithologically indistinguishable from overlying and underlying formations, respectively, and are now included in them, making the Birket Qarun Formation 17 m thick at its type locality (see text). UTM coordinates of the locality are approximately 247.500E X 3262.800N. Upper 2 m of Beadnell'sBirket Qarun Formation is lithologically indistinguishable from overlying shelly limestones and is here included in the Qasr elSagha Formation. With these changes, the Gehannam Formation is 46 m thick, the Birket Qarun Formation is 72 m thick, and the Qasr el-Sagha Formation is 47 m thick at Garet Gehannam (see text). UTM coordinates of the locality are approximately 224.000E x 3246.500N.
PAPERS ON PALEONTOLOGY: NO. 30
30
FIG.26-Photograph of Birket Qarun escarpment north of west end of lake Birket Qarun in vicinity of Beadnell's type section of the Birket Qarun Formation (compare with Fig. 25). Lower slope is upper part of Gehannarn Formation. Vertical cliffs of sandstone in middle of section are Birket Qarun Formation. Upper cliffs and slopes are lower part of Qasr el-Sagha Formation (Umm Rig1 Member). View is to east, and lake is in distance at right side of photograph.
was included, drawn through Geziret el-Qarn, Korallenhiigel, and Gebel Hameier. Beadnell Hugh J. L. Beadnell was a geologist employed by the Geological Survey of Egypt to conduct the first thorough survey of Fayum geology. This was motivated in part by the need to store river water from the Nile for irrigation, and it was carried out contemporaneously with Blanckenhorn's stratigraphic investigations. In his final report, Beadnell (1905, p. 9) stated that the purpose of the survey was "to construct as rapidly as possible a general map of the depression, at the same time laying down in broad outline the chief geological formations and trusting to future opportunity to examine in more detail places of special interest. " Beadnell had several advantages over Schweinfurth, Mayer-Eymar, and Blanckenhorn in his investigation of Fayum geology, including full government logistical support for field work, a staff for drafting of maps and sections, and a sponsor for publication of results. More importantly, he had the advantage of a project of wide
scope that placed observations in a broader context than that available to earlier authors. Beadnell's field party began work in October 1898 in the eastern part of Fayum, progressed to the northern escarpments, and extended mapping as far westward as Garet Gehannam and Wadi Rayan during the spring of 1899. Evidently no field work was done during the winter of 1899-1900. Field work in 1901 was limited to soil and water surveys in the Fayum oasis. Bone beds discovered in 1898 were revisited with C. W. Andrews in April 1901, and again later the same year (Andrews, 1901). Field study was concentrated in continental beds in the upper part of the Fayum sequence during the winter of 1901-1902, and some collecting continued there for two more winters. A second phase of mapping was camed out in the winter of 1902-1903, when a traverse was carried from Garet Gehannam southwestward (with discovery of Wadi Hitan or Zeuglodon Valley) and then eastward back to Wadi Rayan. The neighborhood of Garet Gehannam was further explored in the winter of 1903-1904. In addition to preliminary technical papers, this field work resulted in two classic monographs, the
Geziret el-Qarn Hard brown sandstone w i t h globular concretions Soft gypseous clays, Zeuglodon and other bone
Birket Qarun Fm. Brown sandstone Soft gypseous clays and brown sandstones White shaly marl
Ravine beds = Gehannam Fm.
soft sandy shaly clays
Beadnell (1 905)
FIG. 27-Stratigraphic section of Eocene on the island of Geziret el-Qarn in Birket Qarun in the northern Fayum depression, based on measurements and lithological descriptions of Beadnell (1905, p. 44). Beadnell included the lower 8 m of this section in his Ravine beds (Gehannam Formation) and the upper 25 m in his Birket Qarun series, and considered the top bed here to underlie his section measured on the mainland opposite this island (Fig. 28). Lithologicallythe only bed that should be included in the Birket Qarun Formation is the top 7 m sandstone (see text). UTM coordinates of the locality are approximately270.500E x 3264.000N.
Mainland opposite Geziret el-Qarn Gypseous clays, Plicatula, Ostrea, large vertebrae of Zeuglodon isis Sandstones and gypseous clays, forms plain around Dime, Carolia etc. Gypseous clays
Birket Qarun Fm.
Clays, brown sandstones, occasional limestone, Ostrea, Carolia, Kerunia Hard shelly sandstone over clays with Ostrea, Carolia etc. Alternating sandstones and clays Top of hard brown sandstone with globular concretions [in Fig. 271
Beadnell (1905)
FIG. 28-Stratigraphic section of Eocene on the north shore of Birket Qarun opposite the island of Geziret e l - ~ a r nin the northern Fayum depression, based on measurements and lithological descriptions of Beadnell(1905, p. 45). Beadnell included all of this section in his Birket Qarun series, but lithologically and paleontologically it belongs in the Qasr el-Sagha Formation (see text). UTM coordinates of the locality are approximately 270.500E X 3268.500N.
first by Beadnell (1905) on the topography and geology of Fayum Province, and the second by Andrews (1906) on Tertiary Vertebrata of the Fayum. Beadnell (1901) provided a summary of Fayum stratigraphy that has guided most subsequent work. He divided the marine Eocene into four formations or "series, " overlain by a fifth "fluvio-marine" formation. These are as follows: 5. Fluvio-marine Series (Gebel el Qatrani beds), variegated sands and sandstones, clays, and marls, divided near the summit by one or more thick intercalated lava sheets, upper Eocene to lower Oligocene, 250 m thick [now divided into Khashab
Formation, Widan el-Faras Basalt, and Gebel Qatrani Formation]
4. Qasr el Sara Series (Carolia beds), group of alternating clays, sandstones, and limestones, middle Eocene, equivalent to the upper Mokattam beds of Cairo, 175 m thick [now called Qasr el-Sagha Formation] 3. Birket el Qurun Series (Operculinu-Nummulite beds), clays, sandstones, and calcareous grits, middle Eocene, 60 m thick [now called Birket Qarun Formation]
Qasr el-Sagha Yellow sandy limestone with Anisaster1 = base in Dir Abu Lifa section, Fig. 301 Clays with thin bands of fibrous gypsum Shelly limestone with Turritella. Ostrea, Exogyra, etc. Sandy clays with gypsum Impure limestone with Exogyra, Carolia, Turritella Limestone with Exogyra, Carolia, etc., level of Qasr el-Sagha temple ruin
Qasr el-Sagha Fm. Gypseous sandy clays with occasional oyster-limestone, Kerunia
Hard gray sandstone capping plain to south, 'top of Birket Qurun'
Beadnen (1905)
FIG. 29-Stratigraphic section of Eocene at the Qasr el-Sagha temple ruin in the northern Fayum depression, based on measurements and lithological descriptions of Beadnell(1905, p. 52). Beadnell included all of this section in his Qasr el-Sagha series (Qasr el-Sagha Formation). Eighteen meters of section above level of Qasr el-Sagha temple ruin overlap Blanckenhorn's section here (Fig. 14). UTM coordinates of the locality are approximately 274.800E X 3276.500N.
2.
Ravine Beds (fish-scale marls), white marly limestones and gypseous clays, middle Eocene, 25 m thick [now called Gehannam Formation]
1.
Wadi Rayan Series (Nummulites gizehensis beds), clays, marls, and limestones, middle Eocene, undetermined thickness [now called Wadi Rayan Formation or subdivided into Muela, Midawara, Sath el-Hadid, and Gharaq formations]
The Wadi Rayan Formation forms the valley floor over much of the western part of the Fayum depression, but it is breached and exposed in the southwest at Wadi Rayan and vicinity. The Gehamam Formation borders Birket Qarun and forms the floor of much of the cultivated oasis. The Birket Qarun, Qasr el-Sagha, and Gebel Qatrani formations appear from Beadnell's (1901) descriptions to have corresponded largely to sedimentary rocks exposed in the Birket Qarun, Qasr el-Sagha, and Gebel Qatrani escarpments, respectively, irrespective of lithology. Beadnell (1905) published good stratigraphic sections for all of his marine formations. The type locality of the Wadi Rayan Formation is at Minqar el-Rayan (Fig. 23), where there is a section of limestones, clays, and sands 129 m thick. The top unit is a thick bed of hard snowwhite limestone with Nummulites gizehensis that floors much of the western Fayum depression. This bed can be traced northward from Minqar el-Rayan to Garet Gehan-
nam where the Gehannam Formation ("Ravine beds") rests on top of it. The type locality of the Gehannam Formation is at Garet Gehannam, where Beadnell reported it as being 70 m thick (Fig. 24). However the upper 24 m of this is a thick sandstone Beadnell noted resembles overlying sandstones of the Birket Qarun Formation, and there is no lithological or other reason to include this sandstone in the Gehannam Formation. Removing the upper sandstone, the Gehamam Formation is 46 m thick at its type locality (which is closer to Beadnell's original, 1901, report of a 25 m thickness for the "Ravine beds"). The upper 2 m of Beadnell's Birket Qarun Formation at Garet Gehannam is lithologically indistinguishable from overlying shelly limestones and these are here included in the Qasr el-Sagha Formation. Beadnell (1905) reported the Birket Qarun Formation as being 50 m thick at Garet Gehannam (Fig. 24), but addition of 24 m of sandstones removed from the Gehannam Formation and subtraction of 2 m of shelly limestone moved to the Qasr el-Sagha Formation makes the Birket Qarun Formation 72 m thick here. Finally, the upper part of the section at Garet Gehannam (Fig. 24) is a 45 m unit of nummulitic Carolia, Ostrea, and Turritella-rich limestones and clay shales that Beadnell placed in the Qasr el-Sagha Formation. Addition of 2 m makes this 47 m thick at Garet Gehannam. The type locality of the Birket Qarun Formation is north of the west end of Birket Qarun (Figs. 25, 26). Beadnell (1905, p. 46-47) included 50 m from the middle of this section in the Birket Qarun Formation, but here
Dir Abu Lifa (3-3.5 km NE Qasr el-Sagha) Hard white sandy limestone with numerous shell casts, Echinolampascrameri
False-bedded sand and clay, concretions and bands of ironstone
Hard brown ferruginous sandstone with occasional Zeuglodon vertebrae Clays with massive veins of gypsum Hard yellow calcareous sandstone
Qasr el-Sagha Fm.
Sandy glauconitic clays with gypsum, oysters Limestone full of Carolia, with Exogyra, Ostrea, Kerunia Current-bedded ash-gray sands, plants and vertebrates, 'Astrohelia' in places Hard concretionary sandstone, Turritella Hard purplish clays, occasional fish and crocodile remains Crossbedded sandstone, lignitic bands, remains of Sirenia, Crocodilia Hard brown sandy limestone, Carolia, Turritella Gypseous clays with red ferruginous band, paper shales below Light yellow calcareous sandstone, shark teeth, Turritella, Cardita Slate-blue and brown gypseous clays Yellow sandy limestone with casts of Turritella, Ostrea, etc. Sandy clay Double band of limestone, Astrohelia, mollusks, Moeritherium, Eosiren, Zeuglodon Sandy clay Brown sandy limestone with Gisortia gigantea, 'Alectryonia'clotbeyi, etc. Clays w ~ t hgypsum Sandy limestone with numerous Carolia placunoides, Turritella Gray-blue and brown sandy clays, plant remains Shelly limestone Yellow sandy limestone I= top in Oasr el-Sagha section, Fig. 291
Beadnell 11905)
FIG. 30-Stratigraphic section of Eocene at or n e q Dir Abu Lifa 3-3.5 km northeast of Qasr elSagha temple ruin in the northern Fayum depression, based on measurements and lithological descriptions of Beadnell(1905, p. 50). Beadnell included all of this section in his Qasr el-Sagha series (Qasr el-Sagha Formation). Blanckenhorn's short Klippenecke section (Fig. 15) was measured near here and the Gisom'a bed shown here is probably the same in both sections. Bown and Kraus's Wadi Efreet section (Fig. 31) was measured just west of here, where crossbedded sandstone beds occupy even more of the section. UTM coordinates of the locality are approximately 277.100E x 3278.800N.
again this makes little sense lithologically. The lower 18 m are gray and brown clays more like the underlying Gehannam Formation, and the upper 1.5 m are alternating clay shales and sandy limestones more like the overlying Qasr el-Sagha Formation. The distinctive lithology justifying recognition of a separate formation is the 17 m sequence of soft light-yellow sandstones that forms vertical cliff walls. These sandstones weather to produce clusters of spherical sand bodies in places, but the underlying Gehannam Formation produces these too (and
the overlying Qasr el-Sagha formation includes what appear to be spherical bioherms that Beadnell confused with Birket Qarun spherical sandstone bodies elsewhere, see Chapter VI). The Birket Qarun Formation, as restricted here to a lithologically defined sandstone unit, is 72 m thick at Garet Gehannam but only 17 m thick at its type locality. Beadnell (1905, p. 44) visited the island Geziret elQarn in Birket Qarun and published a 33 m thick section that he regarded as 7.5 m of "Ravine beds" at the
bottom, overlain by 25.5 m of gypseous clays and sandstones of the Birket Qarun Formation (Fig. 27). The top 7 m bed is the only Birket Qarun-like sandstone, and I regard the lower 26 m as Gehamam Formation. Beadnell (1905, p. 45) published a 37 m "Mainland" section measured just north of Birket Qarun on the mainland opposite the island of Geziret el-Qarn (Fig. 28). He regarded all of this section as Birket Qarun Formation, but it is full of Ostiea, Carolia, and Kerunia ("Qerunia"), which are more typical of the Qasr el-Sagha Formation, 'making it more likely that this section is really part of the Qasr el-Sagha Formation. Thus the Birket Qarun Formation is probably only 7 m or so thick in the vicinity of Geziret el-Qarn. Beadnell's (1905, p. 50-52) Qasr el-Sagha Formation section was measured in two parts at two places. The first part was measured at the type locality, the Qasr elSagha temple ruin (Fig. 29; where Blanckenhorn measured the Qasr el-Sagha section shown in Fig. 14). Beadnell's Qasr el-Sagha section is 45 m thick, but only the upper 18 meters overlap Blanckenhorn's section. The main part of Beadnell's Qasr el-Sagha Formation section was measured 3 to 3.5 km northeast of Qasr elSagha in the vicinity of the Coptic cliff-dwelling at Dir Abu Lifa (Fig. 30). This contributes an additional 109 m to the whole, and shows, in the lower part, the alternation of clay shales with limestone "hard beds" described by Blanckenhorn (1903). Beadnell was more impressed than Blanckenhorn by massive cliff exposures of cross-bedded sandstones and clays. Beadnell, like Blanckenhorn, noted the plateau-forming limestone full of Carolia (68-70 m interval in Fig. 30), and the hard white sandy limestone with Echinolampas crameri at the top of the section (106-109 m interval in Fig. 30). Beadnell's Qasr el-Sagha Formation section was 154 m thick (45 m at Qasr el-Sagha and 109 m at Dir Abu Lifa), which he thought included the whole formation. Eight meters of the Mainland section discussed above overlap this, but the remaining 29 m must be added at the base of the Qasr el-Sagha Formation, which makes its total thickness 183 m. Beadnell (1905) measured sections including what he called Birket Qarun series sandstones near Tamia, Lahun, and Qalamsha on the east and south sides of the Fayum depression but these, like Blanckenhorn's Wadi Ramliya section, are isolated, relatively short, and farther southeast (and hence farther onshore) than other localities, making interpretation difficult and questionable. Sandstones in these sections may be unusually thick sandstone beds within the Gehamam Formation. Simple correspondence of the Gebel Qatrani Formation and the Gebel Qatrani escarpment proved unsatisfactory lithologically, and Said (1960) and Bowen and Vondra (1974) subdivided the Gebel Qatrani escarpment, restricting the Gebel Qatrani Formation to beds below the basalt, naming the Widan el-Faras Basalt, and extending
the Khashab Formation to include beds above the basalt. The Qasr el-Sagha escarpment is sometimes divided into two parallel escarpments, but even so all beds in the escarpment(s) belong to the Qasr el-Sagha Formation. The Birket Qarun escarpment includes three distinct lithological units, a lower marly shale unit (Gehannam Formation), an intermediate cliff-forming sandstone (Birket Qarun Formation), and an upper alternating sandy limestone and shale unit (lower part of Qasr elSagha Formation). Beadnell (1901) interpreted the transition from the Qasr el-Sagha Formation to the Gebel Qatrani Formation as "conformable," although these formations are now known to be separated by an unconformity. This null hypothesis of conformity weakened when Blanckenhorn (1903, p. 399) described the "Liicke oder Unterbrechnung" [gap or interruption] between the Gebel Qatrani and Qasr el-Sagha formations (discussed above). Beadnell (1905, p. 55) clarified this further, but interpreted missing upper beds of the Qasr el-Sagha as indicating facies change rather than erosion: From an examination of the [Gebel Qatrani] series in the field, there is no doubt that, in at least the centre of the area, the deposition of the lowest beds was continuous with those of the Qasr el Sagha ... series below. Followed away from the centre ... the series gradually thins out, and eastwards, at Elwat Hialla, some 23 kilometres north of Tamia, has a thickness of only 40 metres, the basal beds being apparently laid on to a bed of limestone of the Qasr el Sagha series about the horizon of Bed 12 in Section XXIII. The junction here is apparently one of perfect conformity as far as the individual beds go, and the peculiar sequence does not seem to be due to ordinary overlap; it appears as if the change from marine to estuarine conditions had set in earlier here than further to the west, with the result that the upper Qasr el Sagha beds are wanting. Moreover, the accumulation of estuarine beds went on so slowly in this locality that the series does not attain to nearly its normal thickness, while further east it dies out altogether. The slight dip to the north is identical in both series, their lithological characters being, however, very different. Barron (1907) favored Blanckenhorn's interpretation over Beadnell's (as did Blanckenhorn, 1921, p. 109; Strougo, 1976a, p. 1139; and Bown and Kraus, 1988, p. 23). Vondra Carl Vondra (1974) studied the Eocene Qasr el-Sagha Formation in connection with research on the overlying Oligocene Gebel Qatrani Formation (Bowen and Vondra, 1974). Vondra gave the thickness of the Qasr el-Sagha Formation as 200 m, although he did not publish any sections himself nor explain how this round number was
determined. Vondra (1974) divided the Qasr el-Sagha Formation into four distinct facies (paraphrased here): 1. Arenaceous bioclastic carbonate f a c k . Basal unit of yellow-orange glauconitic and limonitic, calcareous, silty, fine-grained quartz sandstone, gradational with underlying siltstone or claystone, with abundant sandfilled vertical burrows 2-3 cm in diameter attributed to Callianassa. Basal unit grades upward into 0.5 to 2 m of poorly sorted bioclastic carbonate with admixture of fine quartz sand in matrix of micrite (original lime mud). Very fossiliferous, packed with complete as well as disarticulated and comminuted remains of sheiiy marine invertebrates, including bivalves, gastropods, echinoids, and coelenterates (corals). Assemblages are usually dominated by Turlwstrea, Carolia, Crassostrea, or Turritella, or by a mixture of Turlwstrea and Turritella. Abraded bones or teeth of transitional marine and marine vertebrates are present, and these occasionally include a skull or partially articulated skeleton of a moerithere or sirenian. Carbonized fossil wood fragments are also found. Shelly fossils are recrystallized and selectively dissolved. Orange color is due to oxidized glauconite grains. Bioclastic carbonates grade upward into a 1-2 m unit of sparsely fossiliferous yellow-orange calcareous finegrained quartz sandstone. Sedimentary structures, when present, include horizontal stratification or gently (5') northwest dipping and more steeply (17-23") southeast dipping large scale planar cross-stratification occurring in isolated sets. Uppermost unit composed of up to 1 m white to yellow-orange, very fine-grained, structureless quartz sandstone. Faunal assemblages indicate a firm to mobile sandsilt substrate, and suggest well circulated, moderate to high energy, warm, normal salinity marine coast or bar front environments to more brackish estuarine mouth environments, with water depths generally less than 20 m (E. G. Kauffman in Vondra, 1974). Vondra considered that the four sedimentary units within this facies corresponded to lower shoreface, middle shoreface, beach-upper shoreface, and eolian environments, respectively, and suggested that the arenaceous bioclastic carbonate facies was deposited by shoreward migrating "megaripples" like those found in shallow water of the Bahamas Bank and Recent beaches. 2. Gypsiferous and carbonaceous laminated claystone and siltstone facies. Interbedded with above facies. Pale yellow-brown to dark gray laminated claystone, silty claystone, and argillaceous siltstone ranging in thickness from 1 to 6 m. Sandy in lower portion and fines upward into siltstone and claystone. Fibrous and massive gypsum common. Veinlets of halite also present. Facies is very carbonaceous and contains small fragments of carbonized wood and leaves throughout.
Complete carbonized leaves and leaf impressions common in claystones. These may form beds up to 0.5 m in thickness, and occur as interbedded lignitic paper shales. Invertebrate fossils are very rare. Sedimentary structures are lacking except for lamination and horizontal sand-filled callianassid burrows in the upper 10-20 cm. Facies interpreted to have been deposited in open and restricted shallow lagoons on the lee side of barrier islands. Lignitic paper shales represent leaf accumulations under very low energy conditions on the landward side of lagoons where abundant broad-leafed plants must have lined the shore. Impeded circulation yielded h y ~ i ~ l h i : a;;d j r d e p s i t i ~ c~f ca!cium su!fik rich muds, later mobilized and redeposited as gypsum in diagenetic shrinkage fractures. 3. Interbedded claystone, siltstone, and quartz sandstone facies. Interfingers with both of above facies. Well exposed in prominent cliffs behind Qasr el-Sagha temple ruin. Interbedded units of 10-35 cm thickness fining upward from fine white quartz sandstone to dark gray siltstone and claystone. Each unit constitutes a foreset bed of a large-scale planar cross-stratification set. Foresets dip at 5 ' to northwest and are from 100-200 m in length. Sandstones within each foreset display steeply dipping cross-stratification of planar-delta type. Invertebrate fossils are very rare. Disarticulated and abraded remains of transitional marine and continental vertebrates occur. Finely comminuted plant debris is abundant in siltstones and claystones. Bioturbation structures and burrows are absent. Facies ranges up to 35 m in thickness and can be traced laterally for up to 15 km. This facies was deposited on a rapidly prograding delta front invading shallow brackish marine waters. Fining upward foresets and smaller scale planar-delta type cross-stratification indicate periodic influx of sediment introduced into a quiet lagoon by flood waters of a stream. Deposition was rapid and inhibited bioturbation and development of an invertebrate fauna. 4. Quartz sandstone facies. This is cut into the interbedded claystone, siltstone, and quartz sandstone facies (facies 3). Its basal contact is erosional, and a 1-2 m unit of channel lag intraformational conglomerate overlies this surface. The lag includes siltstone and claystone clash, abraded bones, and reworked shells in a quartz sandstone matrix. This grades into white fine to medium-grained quartz sandstone with occasional thin interlaminations of carbonaceous siltstone and claystone. Large scale trough and planar crossbeds generally indicate northward ~aleocurrents. Invertebrate fossiis are rare. Vertebrate fossils are locally abundant, including marine fish and aquatic marine to transitional-marine reptiles and mammals. All are at least partially disarticulated and many are abraded.
Facies is lenticular, with a concave upward basal contact. It ranges up to 35 m in thickness and 1 km in width. Lithology, basal contact, lateral relationship to other facies, primary structures, and mixed vertebrate fossil fauna suggest this facies is a distributary channel deposit. Three of Vondra's facies are easily recognized in Blanckenhorn's (1903) section at Qasr el-Sagha (Fig. 14) and Beadnell's (1905) sections at Qasr el-Sagha (Fig. 29) and Dir Abu Lifa (Fig. 30), and the fourth is probably present as well. Facies 1, the arenaceous bioclastic carbonate facies, includes most of the bench-forming "hard beds " with Carolia, Ostrea , and Turritella. Facies 2, the gypsiferous and carbonaceous laminated claystone and siltstone facies, includes most of the interbeds between facies 1 hard beds. Facies 3, the interbedded claystone, siltstone, and quartz sandstone facies, includes the thick conspicuously crossbedded units near the top of the sequence labelled as being crossbedded, current-bedded, or false-bedded. Facies 4 is less common, but the "hard brown ferruginous sandstonewith occasional Zeuglodon vertebrae" near the top of the Dir Abu Lifa section (Fig. 30) fits this description, and the "hard yellow calcareous sandstone" below it might be a distributary channel deposit too. Vondra's environmental interpretations for the Qasr elSagha Formation yield a coherent lagoonal mosaic of harder substrates densely inhabited by bivalves and other invertebrates (facies 1) separated by softer less-habitable clay and mud floors (facies 2), with this lagoonal mosaic invaded by prograding delta front (facies 3) and delta distributary (facies 4) deposits. Vondra did not mention either of the two prominent ledge-forming limestones or sandy limestones corresponding to Blanckenhorn's zones 11-6 and 11-8, and these do not appear to fit any of Vondra's Qasr el-Sagha facies. Bowen and Vondra (1974, p. 118) introduced the term "Bare Limestone" for the top-most bed of the Qasr elSagha Formation exposed in Fayum, and described the contact between this and the overlying Gebel Qatrani Formation as "paraconformable," noting that the base of the latter is a persistent, 15-20 m thick, nonresistant, conglomeratic quartz sandstone. Bowen and Vondra's work was important in changing interpretation of the Gebel Qatrani Formation depositional environment from estuarine or fluviomarine with a coastline [i.e., land] not far distant to the south (Beadnell, 1905, p. 53) to "a low, featureless deltaic plain with a loosely sinuous to meandering stream. Gallery forests existed on alluvial ridges (levees) associated with the stream while savannahs may have existed in the interstream areas" (Bowen and Vondra, 1974, p. 135). In Bowen and Vondra's interpretation the coastline was not far distant to the north, and rivers formed the deposits on the planar top of a delta.
Strougo Amin Strougo's first contribution to Fayum stratigraphy was a note in which he argued that the Qasr el-Sagha Formation in Fayum begins with a faunal zone he called the " Cossmannellafajumensis horizon, " corresponding to Blanckenhorn's (1903) zone 11-2 (Strougo, 1974). Later Strougo (1976a) correlated the Ain Musa bed from Gebel Mokattam to the Qasr el-Sagha Formation in Fayum, but another important aspect of this contribution was review of earlier literature on the Qasr el-Sagha - Gebel Qatrani formational contact and discontinuity of sedimentation marking the Eocene-Oligocene boundary in Fayum (Strougo, 1976a, p. 1139): Au Fayoum, une, discontinuitk de skdimentation marque la limite de l'Eoc2ne et de l'Oligoc2ne comme le prouve le dkveloppement suivant. Blanckenhorn (1900)a assimilk h son niveau 11-8 du Gkbel Mokattam (kquivalent du Membre Ain Musa) la couche terminale de la Formation Qasr el Sagha, puissante de 1 m seulement et renfermant de nombreux Echinolampas crameri et Anisaster gibberulus. Ce synchronism amena Barron (6907) h constater que plus de 70 m de roches reconnues par lui duns le district Le Caire-Suez, au-dessus du Membre d'Ain Musa, et appurtenant encore h lJEoc2nesupkrieur, n'avaient pas d'kquivalents au Fayoum 02 le banc ir E. crameri et A. gibberulus est directement subordonnk h la Formation Qatrani, dJ6ge oligoc2ne; il conclut qu'une profonde discontinuitk de skdimentation skpara 1 'Eoc2nesupkrieur de l'Oligoc2ne au Fayoum. ... Nous venons de voir que les couches du Mokattam et de Qasr el Sagha pouvaient &re considkrkes comme homologues sans dij5cultk. Seuls les 10 m du sommet de ce dernier gisement semblent appartenir h une tranche de temps un peu plus rkcente que celle ayant prksidk au dkp8t de la Formation Maadi, h l'est du Caire. I1 n 'en demeure pas moins qu 'une grande partie des couches afleurant duns le district Le Caire-Suez, au dessus du Membre Ain Musa, fait encore dkfaut au Fayoum, ce qui implique lJt+stence d'une discontinuitk de skdimentation h la limite Eoc2ne-Oligoc2ne duns cette derni2re rkgion.
[In Fayum, a discontinuity of sedimentation marks the limit of the Eocene and Oligocene, as the following proves. Blanckenhorn (1900) included the uppermost bed of the Qasr el-Sagha Formation, only 1 m thick and containing numerous Echinolampas crameri and Anisaster gibberulus, as his Gebel Mokattam level 11-8 (equivalent to the Ain Musa member). This synchrony led Barron (1907) to conclude that more than 70 m of rocks he recognized in the Cairo-Suez district, above the Ain Musa member and belonging to the upper Eocene, had no equivalents in Fayum where the E. crameri and A. gibberulus bed is directly beneath the Qatrani For-
mation of Oligocene age. He concluded that a profound discontinuity of sedimentation separated the upper Eocene from the Oligocene in Fayum ... We come to see that the Mokattam and Qasr elSagha beds may be considered as homologs without difficulty. Only the uppermost 10 m of the latter deposit appear to represent a slice of time a little more recent than that at the top of the Maadi Formation east of Cairo. Little remains there of a great part of the beds deposited in the Cairo-Suez district above the Ain Musa member, missing also in Fayum, implying the existence of a discontinuity of sedimentation at the Eocene-Oligocene boundary in the latter region.] Strougo regarded Bowen and Vondra's report of conglomeratic sandstone at the base of the Gebel Qatrani Formation as consistent with this discontinuity.
Abdou and Abdel-Kireem Abdou and Abdel-Kireem (1975) were the first to propose a planktonic foraminifera1 zonation of middle and upper Eocene rocks in Fayum. They found Globigerinatheka semiinvoluta [PIS] in the Gehannam Formation and concluded that it is late Eocene in age. Haggag Abdou and Abdel-Kireem's study was followed by further work by Strougo and Haggag (1984) and by Haggag (1985, 1990). Strougo and Haggag (1984) studied the Gehannam Formation at Quta near the west end of Birket Qarun, found ~loboritalialehneri and Truncorotaloides rohri, and concluded, first, that the Gehannam Formation is a Fayum correlative of the Giushi Member (Giushi Formation) at Gebel Mokattam, and, second, that both formations are middle Eocene in age. The lower 10 m of the Gehannam Formation at Quta produced foraminifera of the Globorotalia lehneri zone [P12], and the overlying 50 m were considered equivalent to the Orbulinoides beckmanni zone [PI31 or Truncorotaloides rohri zone [P14]. The Birket Qarun Formation lacks planktonic foraminifera, but Strougo and Haggag suggested that this formation might be middle Eocene also. One problem is recognition of formational boundaries: it is clear from Strougo and Haggag's (1984) section that what they recognize as Birket Qarun Formation includes shales that would here be placed in the Gehannam Formation. With further investigation, Haggag (1990) determined that the upper part of the Gehannam Formation at Garet Gehannam and at Quta includes Globigerinatheka semiinvoluta [PIS] and is thus late Eocene in age (as Abdou and Abdel-Kireem , 1975, proposed earlier). Spinose planktonic foraminifera characteristic of the middle Eocene end at the top of the T. rohri zone [P14], before G. semiinvoluta appears, and Haggag proposed a new late Eocene Globigerina pseudoampliapertura zone
to fill this gap. As a result, a significant part of the Gehannam Formation is again recognized as being late Eocene in age on the basis of planktonic foraminifera.
Bown and Kraus Thomas Bown and Mary Kraus (1988) included a substantial discussion of the upper Qasr el-Sagha Formation and two important observations on the Birket Qarun Formation in their monograph on the Gebel Qatrani Formation and adjacent rocks in Fayum. Observations on the Birket Qarun Formation will be mentioned first. Bown and Kraus (1988, p. 48) wrote: The earliest appearance of the coast in the immediate Fayum area during the Eocene was in Birket Qarun and (or) Temple Member time with the development of mangrove swamps and offshore subaqueous dunes in much of the region west of Garet Gehannam. Bown first identified mangrove west of Garet Gehannam when we worked together in Wadi Hitan in 1985. At that time we both regarded the mangrove bed as part of the Birket Qarun Formation, but after several more seasons of field work it is clear that mangrove is confined to one narrow zone and the mangrove zone is in the Gehannam Formation underlying "subaqueous dunes " of the Birket Qarun Formation (see Chapter V). Bown and Kraus (1988) adopted Vondra's (1974) thickness estimate of 200 m for the Qasr el-Sagha Formation, but divided the formation into two members rather than four facies. Their upper or Dir Abu Lifa Member measured 77 m thick at its type locality (Wadi Efreet, Fig. 31). Their lower or Temple Member was thus, by subtraction, thought to be 123 m thick (Vondra's 200 m total, minus 77 m placed in the Dir Abu Lifa Member). The dominant lithology of the Dir Abu Lifa Member is crossbedded sandstone, and the Dir Abu Lifa Member appears to be composed of Vondra's facies 3, the interbedded claystone, siltstone, and quartz sandstone facies (delta front), and Vondra's facies 4, the quartz sandstone facies (delta distributary facies). The Temple Member appears to be composed predominantly of Vondra's facies 1, the arenaceous bioclastic carbonate facies, and facies 2, the gypsiferous and carbonaceous laminated claystone and siltstone facies (both shallow lagoonal facies). Grouping into members indicates that different facies associations characterize different parts of the Qasr el-Sagha Formation stratigraphic section. Bown and Kraus (1988, p. 47) interpreted "conglomeratic coquina" beds in the Temple and Dir Abu Lifa members of the Qasr el-Sagha Formation as "strandline lag deposits" that are "overlain by deposits of more alluvial aspect. " I understand each of Bown and Kraus' "strandline lag deposits" to be what Blanckenhorn called a "harte Bank" pard bed] and Vondra called an "arena-
ceous bioclastic carbonate facies" (facies 2). I understand Bown and Kraus' overlying deposits of "alluvial aspect" to be Vondra's "gypsiferous and carbonaceous laminated claystone and siltstone facies" (facies 2). Previous authors interpreted both facies as marine and, from faunal evidence, these can hardly be anything but marine (see Chapter VI). Bown and Kraus (1988, p. 11) described the Qasr elSagha Formation as "conformably overlying" the Birket Qarun Formation, and noted that 15 km west of GaretGehannam and on the northwest shore of Birket Qarun it seems likely that the Temple Member of the Qasr elSagha Formation is actually a facies correlative of at least part of the supposedly older Birket Qarun Formation. The latter observation is clarified by restriction of the Birket Qarun Formation to distinctive cliff-forming sandstones, and inclusion of overlying lagoonal facies in the Qasr el-Sagha Formation (see following chapters). In their abstract, Bown and Kraus (1988, p. 1) characterized the Gebel Qatrani Formation as "conformably overlying" the Qasr el-Sagha Formation. However, in their text they described this boundary as a "conformable to minor erosional unconformity" (fig. 3, p. 9); "no ... major unconformity" (p. 20); or "at least locally marked by a minor erosional unconformity" (p. 20). Bown and Kraus later wrote that "The Gebel Qatrani Formation overlies the upper part of the Qasr el-Sagha Formation with apparent erosional unconformity everywhere the base of the formation is exposed in the Fayum Depression" (p. 22), while in the western Fayum "the lowest beds of the Gebel Qatrani ... lie with apparent conformity on the bare limestone sequence" (p. 22). Finally (p. 23), they cited Beadnell's observation that the Gebel Qatrani contact with the Qasr el-Sagha at Elwat Hialla "though 'conformable,' is with beds lower in the Qasr elSagha section than in the type area," interpreting this as having "resulted from the absence of deposition of the Dir Abu Lifa Member of the upper Qasr el-Sagha Formation. In the Eastern Desert, the Gebel Ahmar beds (= Gebel Qatrani Formation equivalents) lie unconformably on all older rocks." Some of these statements appear contradictory, but they are not contradictory if "conformable" is understood as an adjective meaning formation-scale bedding is parallel, while "conformity" is understood to mean that no erosional s u ~ a c eseparates formations. "Apparent conformity" describes a cryptic erosion surface. Thus the Gebel Qatrani and Qasr el-Sagha formations are conformable because formation-scale bedding is parallel, but the formations are clearly separated by an erosional unconformity. Rasmussen et al. (1992, p. 560) characterize this as a "major" unconformity. The Gebel QatranitQasr el-Sagha unconformity is not conspicuously angular anywhere in Fayum, but is rather, technically, a
disconformity in the northeastern Fayum and a paraconformity farther west. Other authors Other authors contributing to Fayum stratigraphy include Osborn (1907a,b). Osborn (1908) cited Stromer (1907) to justify considering the "Fluvio-Marine Beds" (Gebel Qatrani Formation) as Oligocene rather than upper Eocene. Iskander (1943), in an obscure report, introduced formational names Muela, Midawara, Sath elHadid, and Gharaq as subdivisions of what is here called Wadi Rayan Formation in Fayum. Benthonic and other foraminifera in Fayum have been studied by Shamah and Blondeau (1979), Shamah et al. (1982), and AbdelKireem et al. (1985). Shamah and Blondeau considered the upper part of the Midawara Formation to belong in the Truncorotaloides rohri zone [P14], but this, like inclusion of the Gizehensis and Upper Building Stone members of the Mokattam Formation in the Bartonian (Chapter 11), appears questionable. Khashab (1974) included a good general map and composite stratigraphic chart for the Fayum. Moustafa (1974, p. 49) called the lower part of the Qasr el-Sagha Formation the "Prozeuglodon zone, " which is surely a misnomer considering that Prozeuglodon comes from the Gehannam and Birket Qarun formations but not the Qasr el-Sagha Formation. Ismail and Abdel-Kireem (1975) discussed Fayum stratigraphy. Kappelman (1991) published a preliminary interpretation of paleomagnetic stratigraphy in Fayum, retaining virtually all of the Gebel Qatrani Formation in the Oligocene. Summary Four Eocene formations are found in Fayum. All are marine. The Wadi Rayan Formation is at least 129 m thick, it is mainly Lutetian (middle Eocene) in age, and it was deposited on an open marine continental shelf. The Gehamam Formation is about 46 m thick, of middle to late Eocene age (Bartonian through early Priabonian) on the basis of planktonic foraminifera, and was deposited on a shallow shelf. The Birket Qarun Formation, where it is found, ranges from 7 to 72 m thick, and it is late Eocene in age (early Priabonian). A new environmental interpretation is outlined in Chapter VI. The Qasr el-Sagha Formation is about 183 m thick north of lake Birket Qarun, is late Eocene in age (Priabonian), and was evidently deposited in lagoons and embayments and on the fronts of advancing deltas. Finally, the Gebel Qatrani Formation overlying the marine Eocene Qasr elSagha Formation is continental, it is Oligocene in age, and it is separated from the Qasr el-Sagha Formation by a major unconformity.
Wadi Efreet (2 km NNE Qasr el-Sagha) Upper crossbedded sandstone and mudstone Sandstone and limestone (Bare Limestone) Sandstone
Lower crossbedded sandstone and mudstone
Strandline coquina rich in fossil vertebrate remains Green and gold silty sandstone with crab burrows trandline coquina rich in fossil vertebrate remains reen shale w ~ t hgypsum
Dir Abu Lifa Mbr. Qasr el-Sagha Fm.
8
Green muddy sandstone Green shaly mudstone with gypsum Sandy shale with coquina of rounded shell fragments Calcareous reen shale with Carolia and oysters Golden sanjstone with abraded mollusks
Giant crossbedded sandstone, vertebrate bone, level of type of Apterodon saghensis
Strandline coquina rich in fossil vertebrate remains
Bown and Kraus (1 988)
FIG. 31-Stratigraphic section of Eocene at Wadi Efreet 2 km NNE of Qasr elSagha temple ruin in the northern Fayum depression, based on measurementsand lithological descriptions of Bown and Kraus (1988, p. 13). Bown and Kraus made this the type section of their Dir Abu Lifa Member of the Qasr el8agha Formation. Note predominance of crossbedded sandstone and mudstone units, including upper crossbedded sandstone and mudstone above the Bare Limestone [or Ain Musa bed] at the top of the section. UTM coordinatesof the locality are approximately 276.000E x 3278.500N.
Garet el-Esh Hard limestone with Turritella [Bare Limestone] Brown and gray clay shale with gypsum Soft brown sandstone and siltstone
Brown and gray clay shale with gypsum Sandstone
Qasr el-Sagha Fm.
Multistory Carolia limestone, small oysters at top Hard silty clay, top extensively burrowed Hard silty clay Gray clay shale Flagstone (thin hard sandstone) Gray clay shale Yellow limey sandstone Multistory Ostrea hard bed Dark shale over hard siltstone Sirenian endocast Limey hard bed over Turritella hard bed Gray shale with partial skeleton of Dorudon stromeri Lim y ard bed o u ul tin surface o? w j l t e cross%eadegsa#dstone Black shale, sirenian vertebrae Double limey hard bed, numerous sirenians, Saghacetus osiris skeleton Fine-bedded clay shale with thin sandstones Turritella/Carolia hard bed
Gray clay shale and siltstone
Limestone concretions PDG
- November 2, 1
FIG. 32-New stratigraphic section of Eocene Qasr el-Sagha Formation at Garet el-Esh in the northern Fayum depression. Base of section is not exposed. Garet el-Esh is near the localities Schweinfurth and Blanckenhorn called Zeuglodonberge or Zeuglodonberg (Figs. 18-19) and Zeuglodonberg NW (Fig. 20). Blanckenhorn's zones (1903) are shown at right. UTM coordinates of the locality are approximately 264.500E x 3274.200N.
NEW OBSERVATIONS IN FAYUM New stratigraphic sections were measured in Fayum in 1991 to document the levels and relative ages of cetacean and sirenian skeletal remains collected during past field smons, and to develop a better understanding of Eocene depositional environments and sedimentary facies relationships. These sections were measured through the upper Qasr el-Sagha Formation in the Qasr el-Sagha escarpment at Garet el-Esh; through the Birket Qarun and lower Qasr el-Sagha formations in the Birket Qarun escarpment at Garet Umm Rigl; and through the upper Gehannam, Birket Qarun, Qasr el-Sagha, and lower Gebel Qatrani formations in and near Wadi Hitan (Zeuglodon Valley). Sections in each area are described in turn. These clarify the geometry of the Birket Qarun Formation. Two new members are added to the Qasr elSagha Formation. Finally, geographic trends across northern Fayum are described on the basis of previously published sections illustrated in Chapters I1 and I11 and new sections presented here.
40.5 m level in the Garet el-Esh section. Blanckenhorn placed the 11-5a\II-5b boundary at the top of a distinctive terrace-forming oyster bed, and this is found at the 58 m level in the Garet el-Esh section. Blanckenhorn placed the 11-Sb\II-6 boundary at the base of the Carolia bed with Ostrea that forms the top of Zeuglodonberg (Fig. 19), and this is clearly at the 81 m level in the Garet elEsh section. Blanckenhorn's bed 11-6 is the multistory Carolia limestone with small oysters at the top occupying the interval from 81 to 90 m in the Garet el-Esh section. The interval of gypsiferous clay shales from 90 to 124 m corresponds to Blanckenhorn's zone 11-7. Finally, the top of Garet el-Esh is a hard, 4 m thick, wind-sculpted limestone (Bare Limestone of Bowen and Vondra, 1974) occupying the interval from 124 to 128 m at Garet elEsh. The lower part of the Garet el-Esh section is monotonous gray clay shale, the middle part includes numerous Carolia-Ostrea and Carolia-Turritella hard beds, and the upper part has coarser clastics and thicker limestone units (see section on members of the Qasr elSagha Formation below and also Chapter VI).
GARET EL-ESH Garet el-Esh is a distinctive flat-topped hill on the Qasr el-Sagha escarpment about 12 km west of the Qasr elSagha temple ruin. Garet el-Esh is somewhere near Schweinfurth's Zeuglodonberge and Blanckenhorn's Zeuglodonberg locality (Fig. 18), which is the type locality of Zeuglodon osiris [Saghacetus osiris] . This area has been prospected in recent years to collect additional material and clarify which of several archaeocetes the type specimen represents. In the process, the Garet el-Esh section has yielded several important new partial skeletons of cetaceans and sirenians. The stratigraphic section at Garet el-Esh is about 130 m thick (Fig. 32), and, by comparison with Blanckenhorn's Zeuglodonberg section, the Garet el-Esh section includes Blanckenhorn's biostratigraphic zones 11-4 through 11-8. Blanckenhorn (1903, p. 390-392) placed the 11-4\II-5a boundary at the top of a yellow and red Carolia-Ostrea "marl" with Myliobates and a skull of Eosiren libyca. This hard bed overlies a thin (25 cm) white false-bedded sand. A similar unit is found at the
GARET UMM RIGL Garet Umm Rigl is a hill on the north shore of lake Birket Qarun 16.5 km southwest of Garet el-Esh. This is in the Birket Qarun escarpment, stratigraphically and topographically below the Qasr el-Sagha escarpment. Garet Umm Rigl is east of Garet el-Naqb (Fig. 21) and east of the type section of the Birket Qarun Formation at the west end of Birket Qarun (Figs. 25-26). Vertebrate fossils are rare, but several fragmentary skeletons of interesting archaeocetes were found here in 1985 and 1991. The stratigraphic section at Garet Umm Rigl (Fig. 33) was studied to clarify transitions from the Gehannam Formation to the Birket Qarun Formation, and from the Birket Qarun Formation to the Qasr el-Sagha Formation, as distinguished lithologically. The uppermost 10 m of Gehannam Formation at Garet Umm Rigl is gray clay shale with gypsum. The Birket Qarun Formation is 27 m of yellow sandstone that forms cliffs along much of the
PAPERS ON
PALEONTOLOGY: NO. 30
Garet Umm Rigl Hard bed with Ophiomorpha\Carolia\Ostrea, Kerunia Brown shale with gypsum, rare Basilosaurus, small archaeocete Hard limey sandstone with occasional Ostrea Hard limey sandstone over siltstone, some Turritella Brown shale with gypsum Lime-cemented sandstone Friable brown sandstone, casts of Lucina
Qasr el-Sagha Fm. Shelly hard bed, thick bed of Ostrea, some Turritella
Hard bed with Ophiomorpha\shelly bed\few Turritella Brown shale Red ironstone concretions
Hard yellow sandstone over brown silt
soft yellow sandstone, forms cliffs in places
Birket Qarun Fm.
G e h a n n a m Fm. PDG - November 9. 1991
FIG. 33-New stratigraphic section of Eocene Gehannam, Birket Qarun, and Qasr el-Sagha formations at Garet Umm Rigl in the northern Fayum depression. Base of section is not exposed. Garet Umm Rigl is between Geziret el-Qarn (Fig. 27) and the mainland opposite Geziret el-Qarn (Fig. 28) in the east and Garet el-Naqb (Fig. 21) and the west end of Birket Qarun (Fig. 25) in the west. UTM coordinates of the locality are approximately 253.500E x 326 1.800N.
escarpment. There is a zone in the middle that weathers into the large spherical masses mentioned by Beadnell (1905) as being characteristic of the formation. The lower 65 m of the Qasr el-Sagha Formation exposed at Garet Umm Rigl has a succession of hard beds reminiscent of those in the middle part of the upper Qasr elSagha section at Garet el-Esh. The significance of these is discussed in the section on members of the Qasr elSagha Formation below and in Chapter VI.
WADI HITAN Six sections were studied in Wadi Hitan (Zeuglodon Valley). The first three are short. At locality ZV-54NW (Fig. 34) there is a 35 m succession of gray clay shales and thin terrace-forming marls of the Gehannam Formation, overlain by a distinctive green shale with white gypsum and then sandstone. Traced laterally, the gray clay shales include many skulls and partial skeletons of
NEW OBSERVATIONS IN FAYUM
Wadi Hitan ZV-54NW Sandstone and shale
Birket Qarun Fm.
Green shale with white gypsum
Gray clay shale Marl terrace Marl terrace
Gehannam Fm.
Prozeuglodon skull Prozeuglodon skull Prozeuglodon skull, approx. level of Lobocarcinus concentration
Gray clay shale with Basilosaurus skeleton Yellow sulphurous layer, forms ridge
-
PDG October 29, 1991
FIG.34--New stratigraphic section of Eocene Gehannam and Birket Qarun formations 100 m northwest of locality ZV-54 in Wadi Hitan (Zeuglodon Valley) in the northwestern Fayum depression. Yellow sulphurous layer at base of this section can be traced to middle of ZV-54 section (Fig. 35). UTM coordinatesof the locality are approximately 212.400E x 3245.300N.
--E
Wadi Hitan ZV-54
2 20
C Y o
3
g
Fine sandstone and siltstone, ZV-54 sirenian skeleton at base Gypsiferous clay shale Yellow sulphurous layer, forms ridge
Gehannam Fm.
10
Q
E
Red ironstone concretions
w
3
E
G
0
Calcareous sandstone, weathers into spherical masses PDG
- October 29, 1991
FIG. 35-New stratigraphic section of Eocene Gehannam Formation at locality ZV-54 in Wadi Hitan (Zeuglodon Valley) in the northwestern Fayum depression. Sandstone at top of section represents a local distributary channel deposit. Note spherical masses weathering from sandstone at base of section. This can be traced to top of ZV-70 section (Fig. 36). UTM coordinates of the locality are approximately 213.100E x 3244.600N.
the archaeocetes Basilosaurus and Prozeuglodon. The green shale with white gypsum thins to the south and southwest, but it can be traced, within a few kilometers, into the middle of the Birket Qarun Formation (forming the "Black Layer" marker bed, as at Sandouk el-Borneta; see Figs. 37 and 43). The base of the ZV-54NW section is a low ridge-forming yellow sulphurous layer that can be traced to the middle of the section at locality ZV-54 (Fig. 35). All of this 23 m section is Gehannam Formation. The top bed at ZV-54 is a multistory channel sandstone (with a sirenian skeleton weathering from the base) that probably represents a local distributary channel deposit. The bottom bed at ZV-54 is a calcareous sandstone that weathers into spherical masses. This bed can be traced for a kilometer or so to the northeast
where, at locality ZV-70 (Fig. 36), it caps a section of Gehannam Formation clay shales with white marl, silt, and sandstone bands. Here again, the shales are rich in archaeocete and other vertebrate remains. These three short sections taken together form one composite section of 74 m of Gehannam Formation below the "Black Layer" green shale with gypsum. The upper part of the Gehannam Formation clays here can be traced into Birket Qarun Formation sandstones within a few kilometers to the south. The Sandouk el-Borneta section (Fig. 37) has 26 m of G e h a ~ a mFormation light clay shales with some marl at the base. This is overlain by 57 m of yellow cliffforming sandstones with the "Black Layer" of gray-toblack shale in the middle. There is a bed packed with
Wadi Hitan ZV-70 Hard limey siltstone [Sandstone at base of ZV-54 section] Shale full of red iron-filled Ophiomorpha callianassid burrows White sandstone and hard limey siltstone
Gehannam Fm.
Level of ZV-70 Basilosaurus, ZV-72 Prozeuglodon
Hummocky white layer, whales sawtooth shark, sirenian White layer w ~ t hBas~losaurus,Prozeuglodon, turtle PDG
- October 29, 1991
FIG. 36-New stratigraphic section of Eocene Gehahnarn Formation at locality ZV-70 in Wadi Hitan (Zeuglodon Valley) in the northwesternFayurn depression. Base of section is not exposed. Birket Qarun Formation here is about 57 m thick. UTM coordinates of the locality are approximately2 14.100E X 3245.600N.
Carolia nine meters from the top of the Birket Qarun Formation. Two meters of Qasr el-Sagha Formation overlie the Birket Qarun Formation. This capping unit has a bed packed with two species of oysters at the base (including one with valves up to 15 cm in diameter) and a densely packed, well cemented bed of nummulites overlying this (Fig. 38). The oysters appear to have been swept together before they were deposited on a scoured surface, and they are now buried under 1-2 m of packed and cemented nummulite tests. The high concentration of oysters, deposition on a scoured surface, and burial under packed nummulite tests suggest that this is probably a storm deposit or "tempestite" like others described from the Eocene of Egypt by Aigner (1982, 1983). At Minqar el-Hut, south of Sandouk el-Bometa, the Birket Qarun Formation is very thick (Fig. 39). The Minqar el-Hut section (Fig. 40) has 37 m of Gehannam Formation at the base. This is largely brown shale with gypsum (forming cliffs in places), but there is a complex of hard sandstones and marls near the base that is rich in the large echinoid Schizaster and rich in archaeocete remains (both Basilosaurus and Prozeuglodon). In the interval 33 to 36 m above the base, there is a thick limey hard bed with vertical mangrove pneumatophores weathering from it. This mangrove bed, because of its uniqueness and its position at the top of the Gehannam Formation where overlying Birket Qarun sandstones are thickest, is almost certainly the same mangrove-rich bed (the "Camp White Layer") found a kilometer or so to the north in Wadi Hitan (see Chapter V). The final stratigraphic section measured in Wadi Hitan is the Minqar Abyad section (Fig. 41), which is 269 m thick. It was measured from the hard white marl bed ("Camp White Layer") at our camp (Fig. 42) to the top of the white escarpment at Minqar Abyad 5 km to the northwest. It starts at the top of the Gehannam Forma-
tion, includes a full section of Birket Qarun Formation, a full section of Qasr el-Sagha Formation, and ends in Gebel Qatrani Formation. The Camp White Layer at the base of the section can be traced for a kilometer or so to the east, southeast, and southwest of camp. East and southwest of camp the white layer includes areas rich in mangrove pneumatophores and anchor roots. The Camp White Layer has many skeletons of Basilosaurus and Prozeuglodon weathering from it or from beds within a few meters above and below it. Hind limbs found with skeletons of Basilosaurus described by Gingerich et al. (1990) came from this Camp White Layer at the top of the Gehannam Formation. The Birket Qarun Formation is 50 m thick in the Minqar Abyad section, and it has much the same character as observed at Sandouk el-Bometa. The Qasr elSagha Formation has 35 m of interbedded shales and hard beds at the base, like those observed at Garet Umm Rigl. These are overlain by 40 m of brown shale, much of it covered by blown sand and desert serir, forming a broad featureless plain. Then there is another 37 m unit of interbedded shales and hard beds corresponding to the Temple Member of Bown and Kraus (1988). This is followed by 66 m of brown sandstone, siltstone, and shale, some crossbedded like the interbedded claystone, siltstone, and quartz sandstone facies (Vondra, 1974) characteristic of the Dir Abu Lifa Member of Bown and Kraus (1988). This unit is capped by a shelf-forming shelly limestone that is interpreted as the Bare Limestone of Bowen and Vondra (1974). The uppermost 30 m of the Minqar Abyad section is red and yellow sandstone and siltstone with white bone and white coprolites that is clearly part of the continental Gebel Qatrani Formation. Much of the Gebel Qatrani Formation here is covered by slope wash and inaccessible. The top of the Minqar Abyad section is a 10-18 m thick crossbedded calcareous sandstone that fills paleo-
45
NEWOBSERVATIONSIN FAYUM Sandouk el-Borneta Ostrea and nummulite storm accumulation p . . ... . 80
Qasr el-Sagha Fm.
Yellow sandstone Caralia bed, storm accurnulationO)
Yellow sandstone
Birket Qarun Fm. Gray to black shale (Black Layerl, green clay in places
Yellow sandstone, occasional Basilosau~s,hzwglodon
Hard white marl [Camp White Layerl
Gehannam Fm. Light clay shale, some marl
-
PDG October 28, 1991
FIG. 37-New stratigraphic section of Eocene Gehannam, Birket Qarun, and Qasr elSagha formationsat Sandouk el-Borneta in Wadi Hitan (Zeuglodon Valley) in the northwesternFayum depression. Base of section is not exposed. Birket Qarun Formation here is about 65 m thick. UTM coordinates of the locality are approximately212.600E X 3243.000N.
FIG. 38-Photograph of nummulite and oyster beds capping Birket Qarun sandstone at Sandouk el-Borneta (see section in Fig. 37). Largest oysters have heavy round valves on the order of 15 cm in diameter. Density of oysters, deposition on a scoured surface, and burial under 1-2 m of packed nummulite tests suggest storm deposition.
FIG.39-Photographof Birket Qarun Formation where it forms steep cliffs along the southern escarpmentof Minqar el-Hut. Stratigraphicsection is shown in Fig. 40. View is to north. White stripe in valley floor at lower right of photograph is white marl bed that contains numerous skeletons of Basilosaurus farther to the east. Lower prominencesat left and right center are brown shale with gypsum of Gehannam Formation. Brown shale is overlain by a hard marl with vertical mangrove pneumatophores(not visible at this scale) interpreted as the Camp White Layer (see Figs. 42, 46, and 47) marking the top of the Gehannam Formation in Wadi Hitan north of Minqar el-Hut. Steep cliffs 60-65 m high are entirely Birket Qarun Formation sandstone. Note thick horizontal bedding in otherwise massive linear sandstone body that indicate deposition of a succession of barrier sands. Gray to black shale marker bed found in more northern sections is not found here. Capping bed marks the base of the Qasr el-Sagha Formation locally.
valleys conspicuously scoured as much as 8 m into the underlying red and yellow sand and siltstone. The name Minqar Abyad refers to the gleaming white color this calcareous sandstone gives the whole escarpment. It is filled with rhizoliths like those in the Barite Sandstone illustrated by Bown and Kraus (1988, fig. 27c; possibly this is the Barite Sandstone). Bown and Kraus (1988, p. 19) stated that the Bare Limestone is "very thick (exceeding 10 m)" at Madwar el-Bighal in the western Fayum Depression (Madwar el-Bighal is the plain south of Minqar Abyad), but the Bare Limestone is only 2.5 m thick here. It would be easy to mistake the capping white rhizolith-rich sandstone of the Gebel Qatrani
Formation here for the Bare Limestone of the Qasr elSagha Formation when viewing these from a distance, but the two are very different and easily distinguishable when studied in outcrop or hand specimen.
GEOMETRY OF BIRKET QARUN FORMATION Two formations, the Birket Qarun Formation and the Qasr el-Sagha Formation, were studied in the field. The Birket Qarun Formation of Beadnell (1905) is restricted
Minqar el-Hut
Qasr el-Sagha Fm.
Ostrea bed (storm deposit?)
Yellow sandstone exposed in massive cliffs
Birket Qarun Fm.
Covered slope at base of cliff Hard marl with vertical mangrove pneumatophores Gypsum, weathering out in flat slabs
Brown shale with gypsum, cliff-forming in places
Gehannam Fm. White sandstone and siltstone Hard yellow sandstone White marl, silt, sandstone, many Basilosaurus, Prozeuglodon White fine sandstone Brown shale with gypsum
PDG
- November 1 1
FIG. 40-New stratigraphic section of Eocene Gehannarn, Birket Qarun, and Qasr el-Sagha formations at Minqar el-Hut south of Wadi Hitan (ZeuglodonValley)in the northwesternFayurn depression. Base of section is not exposed. UTM coordinatesof the locality are approximately 212.000E x 3240.500N.
to the cliff-forming yellow sandstones that are so conspicuous above the northwest shore of Birket Qarun, at Garet Gehannam, in Wadi Hitan, and at Minqar el-Hut. The Birket Qarun Formation can be traced along strike in a WSW-ENE direction for 60 km or so, but it is only in Wadi Hitan and at Minqar el-Hut that the Birket Qarun Formation can be studied perpendicular to strike. Lateral variation perpendicular to strike can be illustrated by comparing stratigraphic sections measured at three places: at ZV-54 on the north side of Wadi Hitan (Figs. 34-35), at Sandouk el-Borneta on the south side of Wadi Hitan (Fig. 37), and in the cliffs on the south side of Minqar el-Hut (Fig. 40).
Stratigraphic sections of the Birket Qarun Formation at ZV-54, Sandouk el-Borneta, and Minqar el-Hut are compared and correlated in Figure 43. ZV-54 and Sandouk el-Borneta are about 1.5 km apart, and Sandouk el-Borneta and Minqar el-Hut are about 2 km apart in a north-south transect. This is nearly perpendicular to strike, and it is approximately an offshore-onshore transect. Vertical exaggeration in Figure 43 is about 3 0 x . Principal features to be explained are (1) thickening of lower and upper sandstone units of the Birket Qarun Formation southward from ZV-54, while the distinctive "Black Layer" marker bed becomes thinner southward, (2) change from a 30 m section of Gehannam
PAPERS ON
PALEONTOLOGY: NO. 30
Minqar Abyad [Section continues on next age1 Shelly hard bed, little IateraPcontinuity Carolia hard bed with Turritella, major ridge-former Gray shale with gypsum Limey Carolia hard bed
Qasr el.-Sagha Fm. Brown shale (much covered), forms broad featureless plail7
Limey hard bed over oyster hard bed Gray clay shale Oyster bed TurritellalCarolia hard bed Brown shale with gypsum Turritella hard bed with Carolia beds in lower part Brown clay shale with gypsum Turritella hard bed Large oysters, major ridge-forming hard bed Oyster and Turritella hard bed Carolia bed Soft sandstone with bed of large oysters Limey hard bed Soft sandstone Golden sandstone Limestone Gray shale [Black Layer], gypsum, green clay in places
Birket Qarun Fm.
Soft sandstone (hard in places)
~ a ; dwhite marl [camp White Layerl
,
PDG - November 5 , 1991
FIG. 41-New stratigraphic section of Eocene Gehannam, Birket Qarun, and Qasr el-Sagha formations measured in a transect from the University of Michigan camp in Wadi Hitan (Zeuglodon Valley) to Minqar Abyad 5 km to the northwest in the northwestern Fayum depression. Base of section is top of Gehannam Formation. Birket Qarun Formation is 50 m thick. Qasr el-Sagha Formation is 178 m thick. UTM coordinates of the University of Michigan camp are'approximately 21 1.600E X 3242.100N, and UTM coordinates of Minqar Abyad are , approximately 207.200E x 3244.300N. , \
NEWOBSERVATIONS INFAYUM
Minqar Abyad (cont.) Crossbedded white calcareous sandstone, rhizoliths, fills paleovalleys Scour surface with as much as 8 m of relief
Gebel Qatrani Fm.
Red and yellow sand and siltstone, white bone, coprolites
Slope wash (covered)
Shelly limestone, forms broad ledge (Bare Limestone) Green shale Brown siltstone Green shale with Ophiomorpha at top
Brown fine sandstone and siltstone Brown silt and shale Siltstone Brown silt and shale Limey hard bed over shelly brown silt
Qasr el-Sagha Fm.
Brown silt and shale
Shelly hard bed, Ophiomorpha at base, Turritella at top Crossbedded silt and shale with gypsum, some carbonaceous shale Brown sandstone with Carolia at base Bed of small fluted bivalves, sirenian skeleton
Brown shale, forms undulating plain
[Continued from previous page1
FIG. 41-Continued from previous page.
FIG.42-University of Michigan camp in Wadi Hitan (Zeuglodon Valley). Dip surface in foreground is hard top of Camp White Layer marking the top of the Gehannam Formation and also the Bartonian-Priabonianlowstandof Tethys. Massive sand bodies are erosional remnants of Birket Qarun Formation. Landmark on skyline at left center is Salb AwahAt (Three Sisters). View is to southwest.
gray clay shale below the green marker bed ("Black Layer") at ZV-54 to a 30 m section of Birket Qarun sandstone below the Black Layer at Sandouk el-Borneta within a distance of 1.5 km, and (3) absence of Birket Qarun Formation south and east of Minqar el-Hut. Clear differences in thickness of the same bed, and thickening of some units while others thin in the same direction both indicate that a static layer-cake stratigraphic model is inadequate. Change from 30 m of Gehannam shale to 30 m of Birket Qarun sandstone laterally within a distance of 1.5 km suggests that one or the other formation is a more local facies. Coarser grain size makes it likely that the Birket Qarun Formation is the more local facies, and it does have a more limited geographic distribution. This may explain why the Birket Qarun Formation is not found south and southeast of Minqar el-Hut: it seems unlikely that all Birket Qarun Formation south of Minqar el-Hut would have been eroded leaving the present linear belt of sandstone if, in former times, the formation continued to thicken southward of Minqar el-Hut. Parts of the Birket Qarun Formation are less well consolidated than others, but there is no clear pattern to this. Consequently, the present distribution of the Birket Qarun Formation is likely to approximate its original distribution, and the Formation is reconstructed in Figure 43 as having had a narrow width of about 3-5 km in spite of its demonstrably much greater length.
The main body of the Birket Qarun Formation is presently distributed discontinuously in a linear belt about 60 km long and 5 km wide, and the formation reaches a maximum thickness on the order of 70 m at Garet Gehannam and Minqar el-Hut. This linear,geometry, by itself, is suggestive of an offshore bamer bar, or possibly an offshore tidal-current sand body or sand ridge. Intertonguing of sand and shale units north of ZV-54, and conspicuous thick horizontal bedding like that shown in Figure 39 indicate that the Birket Qarun Formation is probably a bamer bar complex rather than a single bar or ridge. This helps to explain the discontinuous distribution and uneven thickness of sandstones in the formation. Bamer bars are found on linear shorelines where there is a supply of terrigenous clastic sediment and a longshore marine current competent to redistribute this. Tidal current sand bodies are found on shallow shelves with a supply of terrigenous sediment and strong tidal currents. These are not always easy to distinguish (Selley, 1978), and for our purposes it is not absolutely necessary to distinguish them. Both are reworked and removed continuously during normal progradation and regression on a passive continental margin. Barrier bars and tidal ridges are buried and preserved during episodes of marine transgression, and both are thus transgressive systems tracts. Invertebrates including benthic foraminifera (Abdou and Abdel-Kireem, 1975) and fairly abun-
North
South
FIG. 43-Interpretative north-south (seaward-landward) cross-section of Birket Qarun Formation sandstone barrier bar complex in Wadi Hitan, reconstructed from stratigraphic sections in Figs. 34-35, 37, and 40). Note narrow breadth of Birket Qarun Formation shown here (about 5 km) in comparison to an outcrop length of 60 km or more. Gehannam Formation shelf sediments (limestone and dense shale patterns) and Qasr el-Sagha Formation lagoonal sediments (open shale pattern) were evidently deposited contemporaneouslyon opposite sides of the Birket Qarun sandstone barrier bar complex (stippled shading). Vertical exaggeration is about 30 x. Compare with larger-scale stratigraphic model in Figs. 55 and 56.
dant planktonic foraminifera (Strougo and Haggag, 1984; Haggag, 1990) indicate that the Gehannam Formation was deposited in an open marine setting; this lies under and seaward from the Birket Qarun Formation. Foraminifera are rare and oysters common in the Qasr el-Sagha Formation, and this is commonly interpreted as representing estuarine or lagoonal environments (Beadnell, 1905; Cuvillier, 1930; Vondra, 1974; Bown and Kraus, 1988); this lies landward and above the Birket Qarun Formation. Palmenvironmental interpretation of contiguous formations suggests that the Birket Qarun Formation is probably a bamer bar complex rather than a tidal current sand complex. MEMBERS OF QASR EL-SAGHA FORMATION The uppermost Qasr el-Sagha Formation was studied by Bown and Kraus (1988), who recognized and named
the Dir Abu Lifa Member composed of Vondra's interbedded and crossbedded claystone, siltstone, and quartz sandstone facies and Vondra's quartz sandstone facies. Bown and Kraus included the rest of the Qasr el-Sagha Formation in their Temple Member, composed of Vondra's arenaceous bioclastic carbonate facies with hard beds (see below) and Vondra's gypsiferous and carbonaceous laminated claystone and siltstone facies. Study of the middle and lower Qasr el-Sagha Formation west and south of Qasr el-Sagha, at Garet Umm Rigl, and at Minqar Abyad indicate that two additional members should be recognized. These are here called the Harab Member and the Umm Rigl Member. Hardb is an Arabic word referring to a desolate or f&reless place. The Harab Member of the Qasr elSagha Formation is a 30-40 m barren interval of brown shale with few or no hard beds of any kind. It forms broad featureless plains, and separates the Umm Rigl Member below from the Temple Member above. The
Dir Abu Lifa Member
Gebel Mokattam Kamelpass
Korallenhiigel
Gebel ~ c h d a r Tamariskenbucht
(Cairo1
FIG. 45-Sections measured by Blanckenhorn (1900, 1903) in Fayum (six sections at left) compared with Gebel Mokattam (one section at right). Sections are aligned on Blanckenhorn'szone II-8, where present, at top, and zones 11-7, II-6, and II-5 are traced with dashed lines. Note thickening of upper Qasr el-Sagha Formation from Cairo to Fayum, and generally uniform thickness across northern Fayum. Blanckenhorn's sections are not integrated into Fig. 44 because they are consistently less thick than comparable sections measured by others.
type section of the Harab Member is the interval from 85 to 125 m in the Minqar Abyad section (Fig. 41), 2-3 km northwest of Wadi Hitan. This member also forms much of the broad featureless plain of Dimeh between the top of the Birket Qarun escarpment and the base of the Qasr el-Sagha escarpment north of lake Birket Qarun. The Umm Rigl Member is a 30-65 m interval at the base of the Qasr el-Sagha Formation. It is named for Garet Umm Rigl in the Birket Qarun escarpment north of
Birket Qarun, and the type section of this member is the Qasr el-Sagha Formation part of the Garet Umm Rig1 section (Fig. 33). The Umm Rigl Member consists of an alternation of Vondra's arenaceous bioclastic carbonate facies (hard beds) and Vondra's gypsiferous and carbonaceous laminated claystone and siltstone facies, similar to that found in the Temple Member (but separated by the intervening Harab Member).
FIG. 44 (facing page)-Distribution of Birket Qarun and Qasr el-Sagha formations and facies in the northwestern and northern Fayum, based on stratigraphicsections of Beadnell(1905) and Bown and Kraus (1988), and new sections in Figures 32,33, and 41. Sections reaching the top of the formation were aligned on top of the Bare Limestonebed. Minqar Abyad section spans both formations in west. Qasr el-Sagha section is a continuationof Dir Abu Lifa section, lower 29 m of Mainland section and Geziret el-Qarn section extend this farther, and together the four span both formations in east. Interposed lower Qasr el-SaghaFormation sections were aligned on their resistant tops. Thickness of Qasr elSagha Formation at Minqar Abyad in western Fayum (178 m) is very close to that reconstructed by adding parts of the formation documented in Beadnell's Mainland (29 m, Fig. 28), Qasr elSagha (45 m, Fig. 29), and Dir Abu Lifa sections (109 m, Fig. 30) in northern Fayum (183 m total).
GEOGRAPHIC TRENDS The distribution of Birket Qarun and Qasr el-Sagha formations and facies in the northwestern and northern Fayum is compared in Figure 44. This figure shows a general uniformity of thickness of the middle and upper Qasr el-Sagha Formation (Harab, Temple, and Dir Abu Lifa members) across northwestern and northern Fayum, while the lower Qasr el-Sagha Formation (Umm Rig1 Member) is thicker in the middle of this transect. The Birket Qarun Formation is thicker in the west and generally appears to thin to the east (which may also be due to an otherwise negligible difference in the trend of the outcrop belt relative to the trend of the linear formation itself). Stratigraphic sections measured by Blanckenhorn (1900, 1903) are compared in Figure 45. These are not integrated with sections in Figure 44 because Blanckenhorn's sections are consistently less thick than the same or comparable sections measured by Beadnell (1905), by Bown and Kraus (1988), or by me. However, Blanckenhorn's thicknesses appear to be internally consistent and they show a general thickening from the upper Maadi Formation or Wadi Hof Formation at Gebel Mokattam to the upper Qasr el-Sagha Formation in Fayum. The Ain
Musa bed at the top (11-8) appears to thin westward. Zones 11-7, 11-6, and 11-5, comprising most of the comparable sections, thicken between Gebel Mokattam and Qasr el-Sagha and then remain approximately uniform across northern Fayum as far as Zeuglodonberg near Garet el-Esh. For comparison across figures, the Temple Member in Figure 44 corresponds closely to Blanckenhorn's zone 11-4 and the lower part of 11-5 (II5a) in Figure 45. The Dir Abu Lifa Member in Figure 44 corresponds closely to Blanckenhorn's zones 11-Sb, II6, 11-7, and 11-8 in Figure 45. Bown and Kraus (1988, their fig. 40) showed that activation of deep structures ("buried anticlines") influenced the relative thicknesses of Gebel Qatrani Formation that accumulated at different places in northern Fayum during the Oligocene. Figures 44 and 45 here indicate that a greater thickness of Qasr el-Sagha Formation accumulated in Fayum than at Gebel Mokattam, but there is little variation in thickness of the Qasr el-Sagha Formation across northern Fayum. This suggests that the deeper structures were not activated (or reactivated) until the early Oligocene, which may mean activation was associated with opening of the Gulf of Suez. Subsequent outpouring of late Oligocene basalts is usually attributed to opening of the Gulf of Suez.
SEA LEVEL SEQUENCE STRATIGRAPHY Sea level sequence stratigraphy recognizes that many sedimentary formations and groups of formations (depositional sequences or sequence tracts) are bounded by unconformities, and that unconformities on passive continental margins are often caused by rapid falls in global sea level, giving them considerable value for worldwide correlation and chronostratigraphy (Pitman, 1978; Vail et al., 1977; Vail and Hardenbol, 1979; Haq et al., 1987). Most marine stages are sequence tracts or groups of tracts, and sequence stratigraphy provides a natural context for their study. There are major unconformities or other evidence of sea level change at Gebel Mokattam, in Fayum, and elsewhere in Egypt. These are discussed for five areas: Western Desert, Cairo-Giza, Eastern Desert, northwestern Fayum, and western Sinai. The succession of formations in each area is outlined and compared in Figure 52 at the end of this chapter. WSW-ENE orientation of the Eocene Tethyan shoreline in Egypt means that the five areas represent a transect of environments from west to east along the ancient shoreline, but a west-toeast transect is also to some extent an offshore-onshore transect . The age of Fayum formations is reviewed at the end of this chapter, taking account of refinement provided by sea level sequence stratigraphy. Depositional environments are reviewed in Chapter VI, which provides a model for similar consideration of Gebel Mokattam and Eastern Desert formations in the future when these are restudied in the context of major changes in sea level. WESTERN DESERT Sheikh and Faris (1985) described Eocene-Oligocene sections in three oil wells in the Western Desert of Egypt. The first well, North Ghazalat-1, is 500 km west of Cairo and has a continuous sequence of pelagic sediment with no noticeable gap at the Eocene-Oligocene boundary. Eocene and Oligocene parts of the Dabaa orm mi ti on here are apparently perfectly conformable. The second well, Dabaa-1, is 300 km west-northwest of Cairo and is reported to have the top part of planktonic foraminiferal zone P17 missing, indicating a gap at the
Eocene-Oligocene boundary. The third well, East Mubarak-3, is 150 km west-southwest of Cairo. It has a sharp break in lithology where the Dabaa Formation overlies the Ap-mlonia Formation, and several planktonic foraminifera1 zones (PIS-lower P21) are missing. This suggests that erosion associated with the RupelianChattian low sea stand removed whatever was deposited of Priabonian and Rupelian sequence tracts, and the break is now a very large unconformity. CAIRO-GIZA The Eocene-Oligocene section in Cairo is well exposed east of the Nile at Gebel Mokattam, and a partial Eocene section is exposed west of the Nile in Giza and elsewhere. These have been studied by generations of geologists (reviewed in Chapter IT). The Mokattam Formation at Gebel Mokattam is all or mostly Lutetian in age, the Giushi Formation is Bartonian and Priabonian, and the Maadi Formation is Priabonian. Precise age ranges of the Mokattam and Giushi formations need not concern us here; however, it is worthy of note that the celestite and tafla beds of Gebel Mokattam lie within the Giushi Formation (Bauerman and Le Neve Foster, 1869; Blanckenhorn, 1900-Blanckenhorn's zone 11-1 includes the upper Giushi; see Fig. 5). This interval is correlative with an interval rich in celestite in Fayum (see below). If celestite deposition reflects chemical precipitation in a restricted shallow sea as Bauerman and Le Neve Foster (1869) first proposed, this suggests a significantly restricted low sea stand during Giushi time. Blanckenhorn (1921, p. 92) noted the following regarding his zone 11-1 at Gebel Mokattam (Fig. 5): Charakteristisch is d m Vorkommen knollenfaserigen Colestins und einzelner schoner Kristalle aus demselben Mineral sowie die Armut an Fossilien (vereinzelt Taonurus). Beide Umstande hangen wohl mit der Entstehung der Gipsmergel und des Colestin-tajles unter abnormen ozeanographischen Verhaltnissen in vom offenem Meere abgeschlossenen jlachen Lagunen zusammen, wo eine partielle Eindampfung des Meerwassers und Konzentration der Kalk- und Strontiumsulfate stattfand.
[Characteristic are the presence of fibrous nodules of celestite and beautiful single crystals of the same mineral, as well as a paucity of fossils (isolated Taonurus [a trace fossil]). Both circumstances agree well with an origin of the gypsum marl and celestite tafla under abnormal oceanographic conditions in which open sea closes to a shallow lagoon, where a partial evaporation of sea water and concentration of lime and strontium sulfate take place.] The Giushi low sea stand mentioned by Bauerman and Le Neve Foster and by Blanckenhorn probably corresponds to the Bartonian-Priabonian [B-PI sequence boundary shown in the right column of Figure 52. Strougo et al. (1982) described a section at Darb elFayum in Giza where the equivalent interval is marked by an erosion surface indicating disconformity. Faunal constraints suggest that this disconformity also corresponds to the Bartonian-Priabonian [B-PI sequence boundary. The Maadi Formation is similar to the Qasr el-Sagha Formation in lithology and fauna, with abundant oysters, Carolia, etc., but few nummulites. The Gebel Ahmar Formation lies directly on top of the Maadi Formation on the north side of Gebel Mokattam and at Gebel Ahmar (Gebel Akhdar) just north of Gebel Mokattam. The Gebel Ahmar Formation is overlain in turn by basalt a few kilometers east of Gebel Ahmar. The Gebel Ahmar Formation is similar to the Gebel Qatrani Formation, with variegated sediments (Ahmar means red in Arabic) and abundant silicified wood, and it has been considered Oligocene going back at least to Barron (1907). Contact between the marine Maadi Formation and the overlying continental Gebel Ahmar Formation has long been known to lie along an erosional unconformity (Schweinfurth, 1883, p. 719; Barron, 1907; Shukri and Akmal, 1953). The highest bed of the Maadi Formation at Gebel Mokattam is the Ain Musa bed of Barron (1907) described in Chapter 11. This is a bed of hard brown limestone several meters thick that is rich in Anisaster (A. gibberulus) and a small Echinolampas (E. cramer9. The Ain Musa bed is important because it can be recognized 25 km east of Gebel Mokattam at Gebel Anqabia, it can be recognized 80 km east of Gebel Mokattam at Gebel Ataqa (see below), and it can be recognized 80 km southwest of Gebel Mokattam in Fayum. At Gebel Anqabia, 65 m of brown Ostrea and Carolia-rich marine limestone and shale separate the Ain Musa bed from the overlying Gebel Ahmar Formation. This 65 m unit, named the Anqabia Formation by Shukri and Akmal (1953), demonstrates that the erosional surface separating the Maadi Formation and the Gebel Ahmar Formation is a major unconformity, and this is almost certainly the Priabonian-Rupelian [P-R] sequence boundary.
Said (1990, p. 465) indicated that the Gebel Ahmar Formation is 40-100 m thick in the Cairo-Suez district. Basaltic lava flows overlie this near Gebel Anqabia and elsewhere (Barron, 1907), but I am not aware of any radiometric age determinations on the Gebel Anqabia basalts (Meneisy, 1990).
EASTERN DESERT The geology of the desert east of Cairo and Gebel Mokattam was described by Barron (1907). Later Farag and Ismail (1955, 1959) carried out a more detailed investigation in Wadi Hof east of Helwan and 20 km southeast of Gebel Mokattam. Farag and Ismail named five new formations: Gebel Hof, Observatory, Qurn, Wadi Garawi, and Wadi Hof, spanning much of middle and late Eocene time. These cover the same time range as formations exposed at Gebel Mokattam, but lie 20 km or so farther landward and represent slightly different depositional environments. Correlation with Gebel Mokattam is illustrated by Said (1990, figure 24.4 not table 24.3), based on work of Strougo (1985a,b, 1986; see Fig. 4 here). At places in the Eastern Desert, as at Gebel Genefe north of Suez and 100 km east of Gebel Mokattam (Barron, 1907, p. 83 and section I), there is an angular erosional unconformity between limestones of the "lower Mokattam" (Observatory Formation of Farag and Ismail) and Ostrea-Carolia bearing beds of the "upper Mokattam" (Wadi Hof Formation of Farag and Ismail). This is probably the Bartonian-Priabonian [B-PI sequence boundary. Barron (1907, p. 64 and section V) also described an erosional unconformity between the "upper Mokattam" (Wadi Hof Formation) and the Oligocene (Gebel Ahmar Formation) at Gebel Awebed 80 km east of Gebel Mokattam. Barron (1907, p. 85) recorded the presence of 70 m of "upper Mokattam" (Wadi Hof Formation) lying above the Ain Musa bed at Gebel Ataqa just west of Suez and 100 km east of Gebel Mokattam. Removal of the upper Wadi Hof Formation by erosion before deposition of the Gebel Ahmar Formation indicates that a major unconformity separates the two formations in the Eastern Desert. This is almost certainly the PriabonianRupelian [P-R] sequence boundary. Barron (1907, ppli 87-92) argued that the full 70 m of "upper Mokattam was removed by erosion from the top of the Mokattam sequence (top of the Maadi Formation) in Cairo and from the top of the Qasr el-Sagha Formation in Fayum. Basaltic lava flows overly the Gebel Ahmar Formation in the Eastern Desert, and a basaltic neck cuts through Eocene limestones at Gebel Gafra (Barron, 1907). Three age determinations for Eastern Desert basalts range from 1.0 to 22.0 i-2.0 Ma (Meneisy, 1990). 23.0
+
FIG. 46-Camp White Layer at top of Gehannam Formation (foreground) in Wadi Hitan. Sandstones in background are remnants of overlying Birket Qarun Formation. Rod-like structures 1 cm or so in diameter projecting from hard surface or weathering down slope in foregroundaremangrove pneumatophores. Handle of hammer in foreground is about 30 cm long. Salh Awahst landmark is on skyline at right center (compare with Fig. 42). View is to northeast.
FIG. 47-Broken block of Camp White Layer in Wadi Hitan showing hard limestone top in cross-section. This top bed forms an extensive dip slope resistant to erosion. Succession of vertical mangrove pneumatophores dissected by wind erosion are visible below. Block stands about 1.5 m high.
growth). The stratigraphic interval containing mangrove is only at most a few meters thick, suggesting that the time interval of low sea stand was relatively short. FAYUM The stratigraphy of the northwestern part of the Fayum depression has been studied by many investigators (reviewed in Chapter 111). The Eocene section begins with the Wadi Rayan Formation of Lutetian or possibly Lutetian and Bartonian age. This is overlain by the Gehannam Formation of Bartonian and Priabonian age (Haggag, 1990),and by the Birket Qarun and Qasr elSagha formations of Priabonian age. The Oligocene section includes the continental Gebel Qatrani Formation and the Widan el-Faras Basalt, and these are overlain by Miocene Khashab Formation. No major break in sedimentation has been described within the Wadi Rayan Formation or at the transition from Wadi Rayan Formation to Gehannam Formation. However, there is conspicuous evidence of a well marked low sea stand in the middle of the Gehannam Formation (the top of the formation where it is overlain by Birket Qarun Formation). This includes: Abundant mangrove pneumatophores and anchor roots (Figs. 46 and 47) eroding from the Camp White Layer at the top of the Gehannam Formation over a broad area in Wadi Hitan. Pneumatophores are related to aerobic respiration in mangroves, and grow upward out of waterlogged substrates to reach air (Hutchings and Saenger, 1987; they indicate, if not subaerial exposure, that air was within reach of
2.
Discovery of ribs, vertebrae, and both pelves of the estuarine proboscidean Moeritherium (Fig. 48) a few meters below the Camp White Layer at ZV-165 in Wadi Hitan. Moeritherium is not found elsewhere in Fayum except in the upper Qasr el-Sagha Formation.
3.
Celestite filling many mollusks, including Nautilus, Lucina, and Teredo at the GehannamBirket Qarun transition. There is a large tree trunk 18 m long and about 1 m in diameter resting about 4 m below the top of the Camp White Layer (Fig. 49). It is riddled with 'ship worm' (bivalve Teredo) burrows, and must have been sunk or beached as driftwood. Tubes formed as calcareous linings of ship worm borings are filled with celestite (Fig. 50).
All of this evidence taken together indicates a marked interval of low sea stand, possibly with limited subaerial exposure. Patterned cracking of the surface of a femur (Fig. 51) found with a nearly complete skeleton of Basilosaurus in mangrove at Wadi Hitan locality ZV-191 suggests stage 1 subaerial weathering of Behrensmeyer (1978), but this pattern of cracking can also be observed on bone submerged in ponds and never exposed subaerially (D. C. Fisher, pers. comm.).
FIG. 48-Left i ~ o m i n a t oe f Moeritherium sp. from ZV-165 in Wadi Hitan, in lateral view. This compares closely in size and form to the innominate of Moeritherium illustrated by Andrews (1906, p.. 214) and differs from Wadi Hitan Cetacea and Sirenia in having an obturator foramen much larger than the acetabulum. Scale is in cm.
This evidence of low sea stand is unlike any found lower or higher in the Gehannam Formation, higher in the Birket Qarun Formation, or higher in the Qasr elSagha Formation (Moeritherium is known from the upper Qasr el-Sagha Formation, but mangrove has not been reported). The Gehannam Formation was deposited on a shallow shelf in open marine waters, and a part of that deposition occurred during an interval of low sea stand, but there is no evidence of an erosional unconformity of any kind in the area studied. This low sea stand during Gehannam Formation time may help to explain why so many archaeocete skeletons are preserved in Wadi Hitan. Some may have been beached on shallow shoals by retreating tides (although nothing is known of possible tidal ranges here in the Eocene). Alternatively, shallows may have attracted archaeocetes for other reasons: possibly calving in the case of Prozeuglodon and feeding in the case of Basilosaurus (which may not have been totally independent-skulls of immature Prozeuglodon are common, and these often bear impressed tooth marks made by a large predator). The upper Gehannam Formation and lower Birket Qarun Formation have long been known to be unusually rich in celestite (strontium sulfate; Beadnell, 1905), interpreted above to reflect unusually restricted oceanographic conditions where partial evaporation of sea water concentrated lime and strontium sulfate. Interpretation of the Birket Qarun Formation as a barrier bar complex (Chapter IV) is consistent the idea of a low sea stand at its base because barrier bars, as a rule, are only preserved in the stratigraphic record when buried during subsequent transgression. The Birket Qarun Formation is a "transgressive systems tract" in the language of sequence stratigraphy. Evidence of a low sea stand at
FIG. 49-Tree trunk 18 m long and about 1 m in diameter resting some 4 m below the top of the Camp White Layer in Wadi Hitan. This trunk is riddled with 'ship worm' (Teredo) burrows (Fig. 50). View is to northwest, with sandstone remnants of Birket Qarun formation in background.
the top of the Gehannam Formation where it is overlain by Birket Qarun Formation corroborates placement of these formations in sequence tracts TA3.6 and TA4.1, respectively (see Fig. 52), straddling the Bartonian-Priabonian [B-PI low sea stand. Standard interpretation places the Qasr el-Sagha Formation in the upper Eocene and, the Gebel Qatrani Formation in the lower Oligocene (Osborn, 1908; Schlosser, 1911; Said, 1962; Simons, 1968; Fleagle et al., 1986a,b; Bown and Kraus, 1988; Simons and Rasmussen, 1990). These formations are separated by a major unconformity first detected by Blanckenhorn (1903, p. 399) and Beadnell (1905, p. 55), and discussed by Barron (1907, p. 68), Strougo (1976a, p. 1139), and Bown and Kraus (1988, p. 23; see Chapter 111). A minimum of 76 m of erosional relief is associated with the Qasr el-Sagha - Gebel Qatrani formational boundary in parts of Fayum. This is attributed to erosion, or erosion and non-deposition, during marine regression. The 76 m minimum includes 68 m below the Ain Musa bed present at Dir Abu Lifa (Fig. 30) but missing at Elwat Hialla (Beadnell, 1905, p. 55; Barron, 1907, p. 68), and the lesser of 10 m above the Ain Musa bed present at Qasr el-Sagha (Strougo, 1976a, p. 1139) or 8 m of the "upper crossbedded sandstone and mudstone" above the Ain Musa bed at Wadi Efreet (Bown and Kraus, 1988, p. 20). One would hope that erosional scouring responsible for 76 m or more of missing section would leave obvious evidence in the form of an angular unconformity, especially on a continually subsiding continental margin. However, the distance from Qasr el-Sagha or Dir Abu Lifa to Elwat Hialla is on the order of 20 km. Geometri-
FIG.51-Caput and midshaft of left femur of Basilosaurur isis 50--Detai1 of *ship
(Teredo)
that have
completely replaced wood in tree trunk of Fig. 49. Borings are filled with celestite. Pencil is
mm in diameter.
from ZV-191 in Wadi Hitan. Caput is at left, and specimen is shown in dorsal view. Midshaft exhibits pathological hyperostosis in response to breakage during life. Large postmortem cracks developed parallel to midshaft and cancellous texture of bone appear to be desiccation cracks of some kind. Scale is in cm. SINAI
cally, loss of 76 m of sediment over a distance of 20 km requires an angular relationship between beds averaging only about 0.2" (arcsin of 76/20000), which could not possibly be detected in the field. The unconformity probably would be perceptibly angular if it could be viewed perpendicular to the hinge axis of subsidence, but available outcrops all lie parallel to this axis. Removal of 76 m or more of stratigraphic section is clear evidence of a major unconformity and this is almost certainly the Priabonian-Rupelian [P-R] sequence boundary. Other unconformities with evidence of up to 20 m of section missing also occur within the Gebel Qatrani Formation (Bown and Kraus, 1988). Terrestrial fossil mammals come mainly from six levels in the Gebel Qatrani Formation. These are labelled in Figure 52: L-41, quarries A and B, Quarry E, Quarry V, Quarry G, and quarries I and M. The Gebel Qatrani Formation is overlain by the Widan el-Faras Basalt. Radiometric dates on the basalt are 24.7 + 0.4, 27.0 + 3.0, and 31.0 1.0 m.y. (Fleagle et al., 1986a,b). The Gebel Qatrani - widan el-Faras contact was considered "continuous" by Beadnell (1901), "disconformablew by Bowen and Vondra (1974), and a "pronounced erosional unconformity" by Bown and Kraus (1988), illustrating how interpretation of boundaries changes the boundaries become better known. Parts of the Widan el-Faras Basalt were depositOr more of ed in scours indicating 40 regional relief at this unconformity and Kraus; 1988, p. 44).
+
=
Eocene and Oligocene stratigraphy in western Sinai on the east side of the Gulf of Suez is described by Hume et al. (1920), Boukhary and Abdelmalik (1983), Said (1990), and Haggag and Luterbacher (1991). The succession includes the marine Thebes, Darat, and Khaboba formations deposited in deep water, overlain by Tanka Formation shelf sediments. These are overlain by 35 m of red continental Tayiba Formation and then basalt. The Tayiba is separated above and below by unconformities. Radiometric ages of basalt dikes at 2.0 and 18.0 1.0 Ma, Gebel Araba include 31.0 while age determinations on basalt dikes from Wadi Nakhul and Wadi Tayiba are 22.0 1.0 and 21.0 Ma, respectively (Meneisy , 1990). Meneisy (1990, p. 167) considered basalts in the age range 26-22 Ma to reflect vulcanicity related to opening of the Red Sea, but independent age determinations of 31 Ma for basalts in Fayum and Sinai suggest that Gulf of Suez and Red Sea opening started earlier in the Oligocene.
+
+
+
AGE OF FAYUM FORMATIONS The preceding observations are summarized in Figure 52. Low s= stands and unconformities by themselves obviously tell nothing of age, but they begin to be informative when they separate formations or parts of formations correlated with the global time scale on the basis of fossils or other evidence. Sea level stratigraphy is similar to paleomagnetic stratigraphy in
that neither system tells us anything by itself, but both are powerful tools for testing and refining correlations inferred from superposition and faunal or floral succession. The logic of this refinement in Fayum goes as follows. The Qasr el-Sagha and Gebel Qatrani formations are separated by an unconformity in the Fayum that involved erosion of a minimum of 76 m of Qasr el-Sagha sediment in places before deposition of the Gebel Qatrani. This total is close to the minimum of 65 m of Anqabia Formation eroded above the Maadi Formation before deposition of the Gebel Ahmar Formation in the CairoGiza area, and this total is close to the minimum of 70 m eroded from the top of the Wadi Hof Formation before deposition of the Gebel Ahmar Formation in the Eastern Desert. The great thickness of sediment removed by erosion at the Qasr el-Sagha - Gebel Qatrani boundary and the consistency of measurements of erosion separating correlative formations across northern Egypt, taken together, provide clear evidence of a major unconformity. A rapid fall in sea level of 76 m (or more) is required to remove 76 m of shallow marine sediment on a passive continental margin. This happened three times in the middle to late Eocene and Oligocene (Haq et al., 1987): at the Bartonian-Priabonian [B-PI, the Priabonian-Rupelian [P-R], and the Rupelian-Chattian [R-C] sequence boundaries shown in Figure 52. These involved rapid sea level falls of about -100 m, -90 m, and - 140 m, respectively. Sea level falls at any one of the Bartonian-Priabonian [B-PI, Priabonian-Rupelian [P-R], or Rupelian-Chattian [R-C] sequence boundaries would be sufficient to explain removal of 76 m of sediment between deposition of the Qasr el-Sagha and Gebel Qatrani formations. However, radiometric ages on the overlying Widan el-Faras Basalt, taken together, demonstrate that the Gebel Qatrani Formation is older than the Rupelian-Chattian [R-C] sequence boundary. Planktonic foraminifera1 biostratigraphy of the underlying Gehannam Formation demonstrates that the Qasr el-Sagha Formation is younger than the Bartonian-Priabonian [B-PI sequence boundary. Consequently, the Priabonian-Rupelian [P-R] boundary is the only major 'type-1' sequence boundary that can separate the Gebel Qatrani and Qasr el-Sagha formations consistent with constraints on the ages of the two formations. Matching the Gebel Qatrani - Qasr el-Sagha boundary with the Priabonian-Rupelian [P-R] sequence boundary makes it likely that the unconformity at the top of the Gebel Qatrani Formation coincides with the Rupelian-Chattian [R-C] sequence boundary. There is no unconformity at the base of the Qasr el-Sagha Formation, but the low sea stand in the Gehannam Formation at the base of the Birket Qarun Formation coincides with the Bartonian-Priabonian [B-PI boundary. In a recent study, Van Couvering and Harris (1991) claimed that there is no major unconformity between the
Qasr el-Sagha and Gebel Qatrani formations. They then proposed that both formations lie beneath the PriabonianRupelian [P-R] sequence boundary and are thus Priabonian late Eocene in age. A profound change from marine to continental deposition at this boundary has been noted by virtually all geologists and paleontologists who have worked in the field in Fayum, and broader regional evidence summarized here and in Chapter I11 from literature covering the past ninety years makes it clear that a major unconformity separates the Qasr el-Sagha and Gebel Qatrani formations. Consequently it is very unlikely that the Gebel Qatrani Formation is Priabonian in age, and this formation cannot be Eocene according to any current concept of the epoch. Rasmussen et al. (1992) interpreted the lower 157 m of the Gebel Qatrani Formation (including all of the 'lower fossil wood zone' with Duke Quarry L-41, American Museum quames A and B, and Yale Quarry E) as late Eocene. Rasmussen et al. (1992, p. 560) justified this by correlation of mammals from Fayum Quarry E with mammals from Oman localities (Thomas et al., 1989) that Rasmussen et al. characterized as having "paleomagnetic dates" older than the 34 Ma Eocene-Oligocene boundary. However, the Eocene-Oligocene boundary is not defined radiometrically, paleomagnetic correlations are not "dates," and Thomas et al. (1989) themselves regarded the Oman localities as Oligocene. Fossil mammals found at the Oman Thaytiniti locality lie within a normal-polarity magnetic anomaly in association with the Oligocene nummulite Nummulites Jichteli. The anomaly is interpreted as 13N (Thomas et al., 1989), which is Oligocene whatever its radiometric age (Berggren et al., 1985; Haq et al., 1987; Odin and Montanari, 1989; Swisher and Prothero, 1990). If Fayum Quarry E is correlative with Thaytiniti in Oman, then the lower part of the Gebel Qatrani Formation is Oligocene rather than Eocene. Radiometric calibration in Figure 52 requires some comment. The geological time scale is constructed from observation of the superpositional and cross-cutting relationships of strata and formations in the field. Fossils are observed to change in successive strata, which is, on one hand, the material evidence for organic evolution and, on the other hand, the basis for the most complex and informative succession used to correlate and integrate strata worldwide. As discussed above, the position of paleomagnetic stripes ('bar code') and the position of high or low sea stands can be used to test and refine correlations based on fossils and faunal succession, but paleomagnetic stripes and high or low sea stands, by themselves, are meaningless chronologically. Radiometric ages calibrate the result and give us a numerical value for how far back in time events in the Eocene happened, but there are relatively few dated strata, these are often dated using different radiogenic elements and calibration constants, and the derived ages
Age Paleornag.
Chronostratigraphy
W. DESERT
CAIRO
- GIZA
E. DESERT
N W FAYUM
SINAI
Sequence stratigraphy
Dabaa Pelag~cmarine
Appolonia Shelf
FIG. 52-Eocene and Oligocene stratigraphy of northern Egypt. Succession of geological formations is shown for five areas: the Western Desert, Gebel Mokattam and vicinity near Cairo and Giza, the Eastern Desert east of Cairo, northwestern Fayum, and western Sinai. Formations are shown with environment of deposition and thickness when space permits. Asterisks identify important marine and continental mammal-bearing formations. Wavy lines represent unconformities (vertical lines separating pairs of wavy lines depict major unconformities);all are shown with an estimate of minimum thickness of missing section when known. Interpolated age estimates based on radiometric calibration (age) and paleomagneticreversal stratigraphy are shown at left, Eocene-Oligocenechronostratigraphy including magnetochrons and Paleogene planktonic foraminiferal zones (P6B-P22) is shaded at left, and sea level sequence stratigraphy is shaded at right (all taken from Haq et al., 1987). Diamonds depict radiometric ages of Widan el-Faras and other basalts. Letters I, M, G, etc., show positions of land-mammal localities in Gebel Qatrani Formation. Crosshatchingrepresents strata covered or missing in the area studied. Sequencetracts (TA2.4, TA2.5, etc.) separated by heavy broken lines separate important 'type-1' sequence boundaries corresponding to major sedimentary unconformities caused by rapid sea level fall moving shoreline seaward. Type-1 boundaries near the Bartonian-Priabonian transition (B-P), Priabonian-Rupelian transition (P-R), and Rupelian-Chattian (R-C) are shown with approximate magnitude of sea level change in parentheses (estimated as difference between long term maximum and short term minimum for transition). All measures of thickness, missing section, and sea level change are in meters.
are inherently imprecise in comparison to the resolution of paleomagnetic polarity reversals and many sea level changes. Figure 52 illustrates all three points. There are relatively few dated strata: the only relevant radiometric ages are from the Widan el-Faras and correlative basalts at the top of the sections of interest. These are dated using different methods: the Widan el-Faras and correlative basalts were all dated using the decay of radiogenic potassium to argon, but we necessarily compare these to
potassium-argon, argon-argon, rubidium-strontium, and uranium-lead ages elsewhere determined from whole rock or single-crystal samples using a variety of minerals and analytical instruments. Radiometric ages are inherently imprecise: the Widan el-Faras ages range from 24.7 f 0.4 to 31.0 & 1.0 Ma, and correlative basalts elsewhere in Egypt have ages ranging from 22.0 f 2.0 to 31.0 2.0. Radiometric ages are not available for enough strata, are not measured with sufficient uniformity, and do not have the precision to constitute an inde-
+
pendent time scale. Radiometric ages are important for calibration of the geological time scale, but radiometric ages do not now (and probably never will) constitute a Phanerozoic time scale independent of superposition and faunal succession. I have reviewed the differing roles different evidence plays in constructing the geological time scale to emphasize the primacy of fossils (here planktonic foraminifera), the secondary refinement offered by paleomagnetic reversals and sea level stratigraphy, and the tertiary
importance of radiometric calibration. It really makes little difference for the time scale in Figure 52 whether the Eocene-Oligocene boundary is interpolated as being at about 36 Ma (Haq et al., 1987) or at about 34 Ma (Odin and Montanari, 1989; Swisher and Prothero, 1990). Radiometric recalibration would compress some formations slightly and stretch others slightly, but the sequences and correlations of formations and their ages and epochs in relation to stratal stages and series remain the same.
INTERPRETATION OF PALEOENVIRONMENTS One goal of this study is a better understanding of paleoenvironments inhabited by Eocene Cetacea and Sirenia in Egypt. Each Fayum formation yielding marine mammals is reviewed here, and this review is followed by discussion of a general model to explain the succession and progradation of environments observed in Fayum. GEHANNAM FORMATION The middle and upper parts of the Gehannam Formation were studied over a broad area in Wadi Hitan (e.g., Figs. 34-37) and at Minqar el-Hut (Fig. 40). This formation, like the lower part of the overlying Birket Qarun Formation, is of particular interest in yielding many skeletons of the marine archaeocetes Basilosaurus isis and Prozeuglodon atrox. Archaeocete specimens are rarely found together in any concentration, but rather seem to be distributed almost randomly throughout the area studied. Archaeocetes are commonly found as partially articulated skeletons with the axial skeleton more or less complete and articulated, while fore and hind limbs are usually disarticulated and scattered. Skulls are sometimes found separately too. Large Basilosaurus are often more completely articulated than smaller Prozeuglodon, and disarticulation is attributed to the action of sharks and other scavengers. Sirenians are rare in the Gehannam Formation, but they are present and occasionally well preserved. In addition, there is a diverse fauna of sharks, represented by ubiquitous shed teeth. Pristid sawtooth sharks are common, represented by rostra and rostra1 fragments. Large sea turtles specialized for swimming are present, as are smaller turtles. Crocodilians are present but rare. The macroinvertebrate fauna of the Gehamam Formation includes Nuculana, Lucina, Pegophysema, Paraglans, and "Tellina" (Strougo and Haggag, 1984), but it has not, to my knowledge, been studied from an environmental point of view. There are abundant echinoids of the genus Schizaster in the white marl units near the base of the Minqar el-Hut section (Fig. 40). The macroinvertebrates are mostly infaunal, and they are typical of shallow rather than deep sea bottoms. Epifaunal ele-
ments include crabs of the genus Lobocarcinus, which is abundant in the Wadi Hitan ZV-54NW section (Fig. 34). Barnacles (Balanus) sometimes encrust whale bones. The Gehamam Formation has yielded diverse nummulites (Abdel-Kireem et al., 1985) and planktonic foraminifera (Abdou and Abdel-Kireem, 1975; Strougo and Haggag, 1984; Haggag, 1990), and these indicate open marine conditions. Consequently we can be confident that much of the Gehamam Formation was deposited on a shallow but open marine shelf. BIRKET QARUN FORMATION The Birket Qarun Formation has a distinctive geometry, with an outcrop belt as much as 60 km long but never more than about 5 km wide. The Birket Qarun Formation is on the order of 70 m thick at maximum (e.g., at Garet Gehamam, Fig. 24, and Minqar el-Hut, Fig. 40), but thins rapidly perpendicular to the long axis of outcrop. This linear lenticular geometry by itself suggests deposition as an offshore bamer bar complex paralleling the shore line of ancient Tethys (something like the barrier bars or beaches enclosing Lake Burullus and other lagoons shown in Fig. 1). In some places, where the Birket Qarun Formation is thick (as at Minqar el-Hut, Fig. 40, and elsewhere in Wadi Hitan), the bamer complex rests on low sea stand deposits with mangrove (Camp White Layer and equivalents) of the Gehannam Formation. Bamer bars are normally reworked and destroyed during regression, and regression is the common situation on prograding passively-subsiding continental margins like the Egyptian Eocene continental margin studied here. Transgression flooding a shelf is required to bury bars or beaches and thus preserve them (Hoyt, 1967; Selley, 1978). Barrier bar complexes like the Birket Qarun Formation are transgressive systems tracts (Haq et al., 1987), and it is no accident that the Birket Qarun Formation overlies low sea stand deposits of the Gehannam Formation: a bamer bar complex is unlikely to have been preserved in any other setting. The invertebrate and vertebrate faunas of the lower Birket Qarun Formation appear similar to those of the
underlying Gehannam Formation, indicating that both were deposited on a shallow marine shelf. The upper Birket Qarun Formation at Sandouk el-Borneta (Fig. 37) has a bed packed with Carolia that is interpreted as a possible storm deposit (tempestite), and the basal bed of the Qasr el-Sagha Formation there is an Ostrea and nummulite bed interpreted as a storm accumulation like others described from Egypt by Aigner (1982, 1983). Mangrove and estuarine or land mammals like Moeritherium have not been found in the Birket Qarun Formation (except, of course, at its base where this formation lies directly on low sea stand deposits of the Gehannam Formation). Taken together, this negative evidence suggests that the Birket Qarun Formation was a submerged bamer bar rather than beach complex, which is consistent with Bown and Kraus' (1988, p. 48) reference to Birket Qarun "offshore subaqueous dunes." QASR EL-SAGHA FORMATION Four members of the Qasr el-Sagha Formation are recognized here (see Chapter IV), and the sedimentary structures and fauna characteristic of each suggest deposition in distinct environments. Hard beds are important in two of the four members and these will be described first. The two members described by Bown and Kraus (1988) will be discussed next, followed by interpretation of the two new members described in Chapter IV.
Hard beds Blanckenhorn (1903) used the term "harteBank" for some of the beds he described in Fayum. Five of the ridge-forming sandy limestone or limey sandstone units in the lower part of the Garet el-Esh section (Fig. 32) are interpreted as single- or multiple-story "hard beds" (Fig. 53), and these are present in the Garet Umm Rig1 section (Fig. 33) as well. The term "hard bed" is appropriate because each bed is hard and resistant to erosion, and the term is appropriate also because it is general and noncommittal, reflecting a need for more detailed study. Each bed described as a hard bed here may be a hardground (a sea floor deposit formed by synsedimentary lithification), but there is as yet no clear evidence that lithification took place as the sediments accumulated. Hardgrounds reflect specific complex interactions between depositional, biological, and diagenetic processes, and typically preserve part of their fauna in place (Fiirsich, 1979). The hard beds reported here have some of the general characteristics of hardgrounds, but more study will be required to determine if they were lithified as they were deposited. If these do prove to represent hardgrounds, they appear to conform to hardgrounds of Fiirsich's (1979) genetic sequence I.
FIG. 53-Hard bed at 27 m level in Garet el-Esh stratigraphic section (Fig. 32). This is in the Temple Member of the Qasr el-Sagha Formation. Photograph shows thin flat valves of Caroliaplacunoides near the base, red to yellow intermediate zone with mollusk shells and shell fragments, and upper zone rich in Turritella. Section shown here is about 1.5 m thick. Red and yellow color may come from iron hydroxide mineralization, which is characteristic of shallow shelf hardgrounds (Fiirsich, 1979).
Two characteristics of hard beds stand out: (1) they are rich in molluscan remains, and (2) there is a definite succession of bivalves preserved in each hard bed. The richness of mollusks must be due to conditions favorable for growth. Schiifer (1972) identified water currents and clastic sediment contamination as probably the two most important determinants of biotope development. Currents provide oxygen for organismal respiration and growth, but currents may also carry temgenous sediment that interferes with respiration and growth. Qasr elSagha hard beds are shell beds that appear to have developed in areas of sea floor where organisms flourished because they were well oxygenated and because the influx of temgenous clastic sediment was low. The idea of succession in these beds is not new. Blanckenhorn (1903) mentioned banks or benches with Turritella overlying Carolia (Figs. 14, IS), and Ostrea overlying Carolia (Figs. 15, 18), and both are present in the Garet el-Esh section (Fig. 32). Ophiomolpha or
Callianassa burrows are usually found at the base. These are usually overlain by an interval with Carolia. There is then, optionally, an interval of small to mediumsized bivalves. Finally at the top there is an interval rich in Ostrea, Turritella, or Kemnia (or all three). Hard beds are invariably well cemented, which is why they form ridges in the field. Callianassa, the brine shrimp, is an infaunal suspension-feeding crustacean often associated with seagrass meadows (Brasier, 1975). Carolia is an anomiid bivalve that, like living Anomia but unlike oysters, was an epibyssate suspension feeder. Aberhan and Fiirsich (1991) characterize Anomia as iiving on hard substrates, but Carolia had large flat paper-thin valves up to 20 cm in diameter that give an appearance of having been able to virtually "float" on soft mud sea bottoms. Ostrea is a cemented epifaunal suspension feeder living on hard substrates (Aberhan and Fiirsich, 1991). Turritella is a shallow infaunal suspension feeder living on soft substrates. Putting all of this together, it is easy to visualize each hard bed as representing the following succession (from bottom to top): 6. Return to a "normal" influx of clay and silt choking and burying organisms still living on what has now become a cohesive shell bed. 5. Invasion of Turritella as influx of clastic sediment increased. 4. Attachment and growth of one or more generations of Ostrea cemented to this substrate, sometimes with commensal or symbiotic Kerunia and its host present as well. 3. Colonization by one or more generations of other mollusks, whose shells contribute to buildup of a firm substrate. 2. Establishment and growth of one or many generations of epibyssate Carolia. 1. Initial establishment of a seagrass meadow with Callianassa in areas of lagoon floor where the influx of clastics (clay and silt) was unusually low.
There is considerable variation in individual successions, but all share enough of a pattern, with Callianassa below, Carolia grading to other mollusks in the middle, and Ostrea and/or Turritella above, to indicate that some repetitive process was at work. Vondra (1974) described the beds in question as an arenaceous bioclastic carbonate facies, without mentioning succession within them and without elaborating on sources of bioclastic carbonate. Bown and Kraus (1988, p. 47) interpreted "conglomeratic coquina" beds in the Temple and Dir Abu Lifa members as "reworked shoreline lags. " While some conglomeratic coquina beds in the upper Qasr el-Sagha Formation may be shoreline deposits, the mollusks in most are too well preserved (even as steinkerns with shell material leached away) to
represent reworked shoreline lags. Also, a shoreline lag interpretation does not explain the repeated succession from Ophiomorpha-Callianassa to Carolia to Ostrea or Tum'tella and other mollusks, and most of the arenaceous bioclastic carbonate beds probably represent sea floor living surfaces rather than shoreline strands. Temple Member The Temple Member of the Qasr el-Sagha Formation is dominated by two of Vondra's (1974) Qasr el-Sagha facies (see Chapter HI): the arenaceous bioclastic carbonate facies (ficies I), and the gy.psiferous and carbonaceous laminated claystone and siltstone facies (facies 2). As mentioned above, hard beds developed in areas of sea floor where currents were sufficient to provide oxygen enhancing biological productivity but the influx of terrigenous sediment was low. This is where bioclastic carbonates accumulated. Corals abound along many horizons (Beadnell, 1905, p. 53). These are hermatypic scleractinians that require light, clear water, shallow depths (less than 50 m), normal marine salinity, and a firm substrate (Wells, 1967). Oysters are often abundant and these indicate shallow marine to intertidal water depths. Organisms do poorly where the influx of silt and clay is high, and this is where laminated claystones and siltstones accumulated. The two facies alternate in vertical succession in the Temple Member, demonstrating that the influx of silt and clay was localized and spatially variable while the member was being deposited. Dir Abu Lifa Member The dominant lithology of the Dir Abu Lifa Member is crossbedded sandstone of Vondra's facies 3, the interbedded claystone, siltstone, and quartz sandstone facies, which Vondra interpreted as forming on a delta front. A delta front is as far downstream as a river-sourced submarine current transports terrigenous clastics, and this is where most of its sediment load is dropped. Vondra's facies 4, the quartz sandstone facies, is-&so part of the Dir Abu Lifa Member and Vondra interpreted this as a delta distributary facies. Delta distributary channels are found less far downstream where river-sourced submarine currents of higher energy continue transportation of most temgenous sediment and leave only the coarsest fraction behind. Bown and Kraus introduced a novel fluvial interpretation of the Qasr el-Sagha Formation, meaning that they considered much of it to have been deposited by rivers. Bown and Kraus (1988, p. 46-47) reinterpreted Vondra's (1974) interbedded claystone, siltstone, and quartz sandstone facies (facies 3~above)and his quartz sandstone facies (facies 4) as having been deposited by rivers rather than prograding deltas, writing:
These data are indeed consistent with a delta debouching into a bay developed more or less to the north, as suggested by Vondra. However, the contrasting dip directions (185", 229 ",345", and 355") recorded by us at localities east and west of the Qasr el-Sagha Temple, our recognition of west- or west-northwestoriented channels within this sequence, and internal (intraset) stratification showing flow directions of 255" to 310" (45" to 100" different from the flow direction suggested by Vondra's 'sloping surface of the delta front') indicate a somewhat different, nondeltaic origin. ... In the Qasr el-Sagha Formation, there is a 45" to 100" disparity between the dip directions of the giant foresets and the large-scale intrasets. This suggests that the giant cross sets in the bottom of the Dir Abu Lifa Member represent lateral accretion deposits that formed within stream channels. Vondra (1974, p. 86) stated that the foresets dip "to the northwest" (i.e., at a bearing averaging about 31S0, or say, 295" to 335"), so it is not clear where the "45" to 100" disparity" comes from. Neither Vondra nor Bown and Kraus indicated the number or values of their measurements, and "sloping surfaces of delta fronts" are bound to be curved in any case (or even lobed), weakening this as an argument for fluvial rather than delta front deposition. The Temple Member appears to be composed predominantly of Vondra's (1974) Qasr el-Sagha facies 1, the arenaceous bioclastic carbonate facies, and facies 2, the gypsiferous and carbonaceous laminated claystone and siltstone facies (both shallow lagoonal facies). The Dir Abu Lifa Member is dominated by a different pair of Vondra's Qasr el-Sagha facies: the interbedded claystone, siltstone, and quartz sandstone facies (facies 3), and the quartz sandstone facies (facies 4). These are interpreted as prograding delta front and delta distributary deposits, with temgenous sediment predominating. Grouping into members indicates that different facies associations characterize different parts of the Qasr elSagha Formation stratigraphic section. Hermatypic scleractinian corals (including "Astrohelia" of Mayer-Eymar) are reported from the giant crossbedded sandstone sequence of Bown and Kraus (1988, p. 14; see Figs. 14, 30; Blanckenhorn, 1903; Beadnell, 1905), making it very unlikely that this is a river deposit.
Umrn Rigl Member The Urnm Rigl Member of the Qasr el-Sagha Formation (Chapter IV), like the Temple Member, is dominated by two of Vondra's (1974) Qasr el-Sagha facies: the arenaceous bioclastic carbonate facies (facies I), and the gypsiferous and carbonaceous laminated claystone and siltstone facies (facies 2). Here again, the two facies alternate in vertical succession. Hard beds developed in areas of sea floor where currents of clear water provided
oxygen, enhancing biological productivity, while silt and clay were deposited in other areas by currents clouded with temgenous sediment. The Urnm Rigl and Temple members are separated stratigraphically, but they are similar lithologically. One faunal difference may be significant. Kerunia cornuta Mayer-Eymar 1899 (1900) is a distinctive problematical fossil currently interpreted, questionably, as composed of calcareous mats of periderm of hydractinians colonizing the external surfaces of gastropod shells inhabited by hermit crabs and living symbiotically with the crabs (Hill and Wells, 1956). The type specimen of K. cornuta came from the Urnm Rigl Member near Dimeh, and this fossil is much more common in the Urnm Rigl Member of the Qasr el-Sagha Formation than it is in the Temple Member. A better understanding of the form and function of Kerunia (currently under study by A. Seilacher) may clarify palwecological differences between the Urnm Rigl and Temple members. East of Dimeh, the Urnm Rigl Member includes a succession of beds above the north shore of Birket Qarun weathering to reveal circular or oval masses that Beadnell (1905, p. 71) confused with spherical Birket Qarun sandstone bodies found elsewhere. These oval masses (Fig. 54) appear to be calcareous bioherms of some kind. They are reminiscent of stromatolitic bioherms described by Whybrow et al. (1987) from Saudi Arabia, but their origin is unknown (they may, for example, have been constructed by calcareous marine sponges rather than stromatolites). Interpretation is complicated because the undersides of these are often bored (Beadnell, 1905, fig. 7) by Pliocene mollusks (Schweinfurth's "Pholaden"), and some fish bones and other vertebrate fossils found here may have been reworked by a Pliocene sea from overlying members of the Qasr el-Sagha Formation. Harab Member The Harab Member (Chapter IV) is so-named because it is composed of shales that weather as featureless plains. This member is also featureless in terms of sedimentary structures and in terms of fossils, by comparison with other members of the Qasr el-Sagha Formation. It is a monotonous sequence of Vondra's gypsiferous and carbonaceous laminated claystone and siltstone facies (facies 2) without the siltstone. Sedimentary structures and fossils are not available to aid interpretation, which is tentatively attributed to deposition in deeper less-aerated water without the currents needed to provide oxygen or distribute silt and sand. GEBEL QATRANI FORMATION Paleoenvironments of the Gebel Qatrani Formation have recently been studied and reviewed by Bown et al. (1982) and Bown and Kraus (1988). Most of the Gebel
:dm aql tt! (8861 'mWI Pm mO€If ~ ~ '~JPUOA 6 1 pm u a m q ) uo!lemro~ mwnb laqa~)pquau!luo:, aqr q!fi 'smo11oj se s! uo!ssamns lwaua%a u -Allm!qder% -oa% suo!1!sod qe!pamrau! u! punoj aq plnoqs quam -uo~!~uaoaled qe!panuqu~ *@]uau!luor,alom r(paua% ale sluamo~!rrnaoa1ed ~ a e pue l auuem alom Allwaua% ale s l u a m o q ~ u a o a l dJa!lm '~dA%g JO 3!ozoua3 aq) y pauasqo sv -am!l q % n o qp~emeasarrom Allwaua% s)nauruoJ!Aua po!l!sodap lepl sueam uo!1epe~%o~d *uo!ssa~%a~ jo p ~ e m Ala4~e1 ~ Alluanbasum s! j d L 2 ~UI s A q a ~ jo hro,s!q D!ozouaD Alma aql pue 'uo!s - W J % ~ Jo) ~nalerr!nba Alleuo!l3uy S! U O ! ~ ~ ~ J % O 'an![ J ~ -aloqs aql ~ t ! pue1-eas aql jo uo!l!sod jo s w a i q .3!ozoua3 Apea a q jo q3nm %uunpalaq uo!l!puo:, pmrou aql s e u0!1qw.x%o~d ~ leg1 -3!pu! sAq1a~ p~emo)1dBg s s o ~ ms)uamo~!~uaoapd jo uo!ssa%o~d p~emqyou Alpaua% e pue 'p~emeas ahom 01 quam -uoJ!lzua leuo!l!sodap sasne3 s ! *muap!sqns ~ o)anp uoy - v p o m m m jo a e aql ~ V x a Iuam!pas snoua%pqpue 3!1se13o!q JO Alddns jo q e aql ~ uaqM su!%~am~suau!~uo:, %u!p!sqns Ala~!smd no no!,!pum pnuou aql s! uo!le - p e ~ % o ~*uo!ppa%o~d d jo 1mga aql %uuap!sum Alsnoau
-qnm!s 1noqlw m d e d jo a u q aql y paluasqo swam -uoJ!rrua jo muanbas aq1 l a ~ & a q01 alq!ssodm! s! fl
-Lvpm am Laql sa slarru jo saq3ea~ram01 aql u! punoj Lpo!se3~oslam suepaqs a u m q pql saimpu! A~qeqo~d q3!q~ 'suo!le~ - m ~ a u !aupem aql jo auo m o ~IOU j s! j! ' J ~ A ~ M O H'(2s '%!du! m o q s la~al)I h e n o se IaAal ames aql ~e U O ! ~ -euuoj aq1 jo l ~ e d~addnaql q 0 hrrmoy oepaqs e jo squ ~ ~ V ! ~ O S pue S B l l q s POO% e S! S!U -uo!1enuog p a l e 0 laqaf) aql moy u ~ o s!q ~ e m m wauuem auo *(9681'S681 ' ~ e m h -1aLew jo ,,ma?~?.jiu?U~?J~UOJ., aql '-4.a) uo!1enuoj aq1 jo yed ~ a d d naql u! mooq uaaq %uolarreq suo!le@3~qu! a u p m pue 'larral ms la paa!sodap aJaM uo!leauoj am JO stred leqr %u!le3!pu! 'smeld u! punoj s! arro~% - u e ~*u!eld p1seo3 puelmoI p!do~lqns 01 p ! d o ~ l e uo pqsodap sem pue puau!1um s! uo!1emod p a l e 0
-3saaqnos 01 s! marl\ *(qoq 10) nogarmoj a @ ~ p l a r m b a q j o slaqmam ~a3nnoXm o y p ~ r o w a aq r h m r o a3a a n a x q d j o aq Lam araq pnnoj t p a a p w sanoq ataJqaEran Jaqao p w qs!d * p w seas @!q a n a m l d a $n!~np W p n n n ! p w pasodxa araw Xaq uaqM sTsnl1om a n p m Xq paloq naaq anaq 01 re add^ p w 'suo!1mro~d p r w l JO ap!sJapnn a q no ~lanpeagXq paq!msap s%u!~oqmoqs Xaqc~ * p n qamos j o smJaqo!q snoara:,p:, aq 01 raadda sassam @no asaqL -alaqwasla pnnoj no!lamrod n m b layrrg a q JO sao!1a~:,no~ ano~sparesp u a q d s q l a s~a q pasquo:, (ZHL *d '5061) Ilanpeag *mnLagwaquou a q n! qam!a JO lsaa p m u r n 0 Jaqryg JO w o n no!~em~o,j[ s@as-la r s e b a q j o Jaqmapq 18% m m n a q moy 8n!raqvaw sassem p n o r o m l n : , r ! 3 ~ ~- 3 ~
NNW Tethys Sea
GEBEL MOKATTAM
SSE African Continent
FIG. 55-Idealized sea level sequence stratigraphicmodel constructed to explain deposition of shallow marine formations observed in middle and late Eocene of northern Egypt (compare with Fig. 56). Succession of formations observed at Gebel Mokattam is shown in box. Model is NNW-SSE transect perpendicular to the southern Tethys - northern Africa coastline with open shallow shelf, barrier bar, lagoon, delta front, and coastal plain facies. Barrier bar and lagoonal sediments and non-lagoonal delta front sediments represent alternate environmentsand would not have been deposited simultaneously in the same area. Cycles of sea level change depositing successive sequence tracts are shown with uppercase letters: A, marine transgression due to rapid isostatic sea level rise that exceeds regression due to progradation; B, normal regression due to progradation on slowly subsiding passive continental margin; C, major regression due to isostatic sea level fall. Giushi Formation includes highstand and lowstand systems tracts that accumulated during Bartonian and probably early Priabonian time (middle-to-late Eocene) in open shallow shelf environments. Maadi Formationincludeshighstand systemstracts that accumulatedduringPriaboniantime (late Eocene) in lagoonal environments (black lines represent hard beds deposited on margins of inner and outer lagoon). Note that sloping delta front deposits are not recorded at Gebel Mokattam. Barrier bars or beaches protecting Maadi lagoon were not preserved during regression due to bar erosion associated with progradation on slowly subsiding passive continental margin. Gebel Ahmar Formation includes continental systems tracts that accumulated during Rupelian time (early Oligocene) in riverine environmentson prograding delta plains. Vertical exaggerationhere is on the order of 100x.
7. Continental Gebel Qatrani Formation 6. Delta front and delta distributary deposits of the Dir Abu Lifa Member 5. Oxygenated shallow inner-lagoon shelf with hard beds of the Temple Member 4. Low energy deeper water of the Harab Member 3. Oxygenated shallow outer-lagoon shelf with hard beds of the Umm Rig1 Member 2. Bamer bar deposits of the Birket Qarun Formation 1. Shallow open shelf environments of the Gehannam Formation This sequence of ancient environments observed vertically in Fayum is the same as the sequence of environments observed in a transect from the Mediterranean Sea across Lake Burullus and onto the Nile Delta today. There is open ocean (equivalent to the Eocene Gehannam Formation) on the seaward side of the barrier bars and beaches (Birket Qarun Formation) enclosing Lake Burullus, and this lagoon has a shallow energized and oxygenated outer part (Umm Rig1 Member), a deeper central part (Harab
Member), and a shallow energized and oxygenated inner part (Temple Member). There is also an inner margin dominated by temgenous sedimentation (Dir Abu Lifa Member) equivalent to occasional delta front deposition we might expect from lateral migration of the Rosetta branch of the Nile to debouch where Lake Burullus used to be. Much of the surface of the Nile Delta is aerially exposed and continental (Gebel Qatrani Formation). By this interpretation three of the Qasr el-Sagha members represent different environments within a lagoon. The fourth member is deltaic, which is incompatible with a lagoonal environment because a rapid influx of clastics would soon fill any lagoon. Lagoonal and deltaic sedimentary environments alternate along the marine front of the Nile delta today (Fig. I), and this was probably true on the Eocene coastline as well. A dynamic model showing Egyptian Eocene palmenvironments and their progradation, integrated with major cycles of sea level change, is illustrated in Figures 55 and 56. The model was developed to explain
NNW Tethys Sea
SSE FAYUM
African Continent
~irkep~aru Frn. n
I
FIG. 56-Idealized sea level sequence stratigraphic model constructed to explain deposition of shallow marine formations observed in Eocene of northern Egypt (compare with Fig. 55). Succession of formations observed in Fayum is shown in box. Model is NNW-SSE transect perpendicularto the southern Tethys - northern Africa coastline with open shallow shelf, barrier bar, lagoon, delta front, and coastal plain facies. Barrier bar and lagoonal sediments and non-lagoonal delta front sediments represent alternate environments and would not have been deposited simultaneously in the same area. Cycles of sea level change depositing successive sequence tracts are shown with uppercase letters: A, marine transgression due to rapid isostatic sea level rise that exceeds regression due to progradation; B, normal regression due to progradation on slowly subsiding passive continental margin; C , major regression due to isostatic sea level fall. Gehannam Formation includes highstand and lowstand systems tracts that accumulated during Bartonian and Priabonian time (middle-to-late Eocene) in open shallow shelf environments. Birket Qarun Formation shown in black is a barrier bar transgressive systems tract that accumulated at beginning of Priabonian time (late Eocene) and was buried during isostatic sea level rise. Qasr el-Sagha Formation includes highstand systems tracts that accumulated during Priabonian time (late Eocene) in lagoonal environments (black lines represent hard beds deposited on margins of inner and outer lagoon). Sloping delta front deposits (shown with sloping lines and representing, e.g., the Dir Abu Lifa Member) build out from shore and may obliterate or completely fill lagoons (not shown here). Gebel Qatrani Formation includes continental systems tracts that accumulated during Rupelian time (early Oligocene) in riverine environments on prograding delta plains. Vertical exaggeration here is on the order of 100X .
how Fayum formations were related to each other as depositional facies in space and through time (Fig. 56). The model yields predictions about facies and unconformities to be expected at Gebel Mokattam (Fig. 5 3 , which was a little farther seaward during the Eocene (this is inferred from the WSW-ENE trend of the ancient shoreline documented, for example, by the outcrop trend of barrier bars of the Birket Qarun Formation). Formations, facies, and unconformities at Gebel Mokattam have not yet been studied in detail to see whether they corroborate the new model, but I expect that this dynamic sequence stratigraphic model will explain the distribution of facies there better than previous static 'layer cake' models. Figure 56 shows how sedimentary facies are related to each other offshore-onshore, how these are related vertically, and how low sea stands offshore propagate as erosional unconformities onshore. Marine shelf environments shallow landward, and one usually encounters
either a barrier bar and lagoon or an active delta front in moving onshore. This can be seen today, for example, in traversing the Mediterranean and Lake Burullus to reach the continental top of the Nile Delta, or in moving from the Mediterranean across the active delta front of the Rosetta branch of the Nile. Shelf sediments are characteristically dominated by carbonates. Lagoons may include four distinct environments: a sheltering coarse clastic (sand) barrier bar or beach, an outer shallows (with both carbonates and fine clastics), a central deep (fine clastics), and an inner shallows (carbonates and fine clastics). Delta fronts include terrigenous coarse and fine clastics. In places in Fayum, shelf sediments of the Gehannam Formation grade laterally into barrier sediments of the Birket Qarun Formation, and other lateral transitions will probably be discovered as they are sought. The Dir Abu Lifa Member of the Qasr el-Sagha Formation is deltaic, reflecting deposition in the most
landward marine environments, with a strong influx of terrigenous clastics. This probably represents an alternate transect intersecting a Rosetta-like active delta with delta-front deposits. Extensive hard limestones like Blanckenhorn's beds 11-6 and 11-8 (e.g., Fig. 32) in the Dir Abu Lifa Member may be interdeltaic shelf carbonates deposited when delta clastics were diverted elsewhere. The Dir Abu Lifa Member is overlain by continental clastics of the Gebel Qatrani Formation, marking the end of a major phase of marine deposition in Egypt. Finally, propagation of low sea stands offshore into unconformities onshore helps to explain why the Gehannam-to-Birket Qarun transition is so different from the
Qasr el-Sagha to Gebel Qatrani transition even though both are thought to be associated with major eustatic low sea stands. The former transition includes evidence of shoreline facies (especially mangrove), and shoreline facies would be expected in the Qasr el-Sagha-to-Gebel Qatrani transition too if it was a continuous smooth transition from marine to continental sedimentation. Absence of mangrove at the top of the Qasr el-Sagha Formation and at the base of the Gebel Qatrani Formation is consistent with this contact being a major unconfonnity. Mangrove remains are present in places higher in the Gebel Qatrani Formation (Bown and Kraus, 1988, p. 3 I), and these probably grew during intervals of high sea stand flooding otherwise continental environments.
VII
MARINE MAMMA1JS AND LOCALITIES In the nineteenth and early twentieth centuries, fossil by Dames (1883a,b), and the collection is now in the vertebrates were collected opportunistically as they were Museum f i r Naturkunde in Berlin. It includes at least found at Gebel Mokattam, usually by workers quarrying three species, including Prozeuglodon atrox and Basilostone for building and other purposes. Schweinfurth saurus isis, which are best known from the Gehamam (1883) mentioned that quamers never failed to offer and Birket Qarun formations of Wadi Hitan. All of shark teeth (lisrin or "tongue" stones) to tourists, and one Schweinfurth's Geziret el-Qarn specimens were found in can safely assume that mammals were known to have the second highest bed on the island (Fig. 27), which monetary value as well. Some were purchased by Beadnell (1905) regarded as part of the Birket Qarun geologists, paleontologists, and museum representatives, Formation. As discussed in Chapters I11 and IV, this is which means these can have had little accompanying here interpreted as the uppermost bed of the Gehamam locality or stratigraphic information. The type specimens Formation. In either case, the age of the collection is of Eotherium aegyptiacum Owen (1875), "Manatus " probably earliest Priabonian (the uppermost Gehamam coulombi Filhol(1878), Protocetus atavus Fraas (1904a), Formation in this area is probably Priabonian in age"Mesocetus" schweinfirthi Fraas (1904a), Protosiren fide Abdou and Abdel-Kireem, 1975; Haggag, 1990). The first cetacean species named from Egypt was Zeugfraasi Abel (1907), Eotherium (Eosiren) abeli Sickenberg (1934), and Eotherium majus Zdansky (1938) may all lodon osiris described by Dames (1894), based on a have been acquired this way. In contrast, most marine specimen collected by Schweinfurth in 1886 at his ~e "12%km im Westen mammal specimens from Fayum were discovered in Zeuglodonberge or P - ~ e r locality place in the field and collected by professionals, so their vom alten Tempelbau" [Qasr el-Sagha temple]. The species is here placed in a new genus Saghacetus (see localities and stratigraphic levels are better known. Type specimens and published type localities of Table 1, footnote 3). Schweinfurth (1886, p. 139) Egyptian Eocene Cetacea and Sirenia, listed in Tables 1 described the type locality as being in his AAAP zone and 2, are discussed in the order in which they were (Fig. 5). Blanckenhorn described it as being in his 11-5a described. Few are as well documented as one would zone (Fig. 19). Several attempts in recent years to like, but most are known sufficiently to place a type relocate the hill or hills called Zeuglodonberg(e) have all within a formation, constrain its age, and permit some failed, not because there are no hills yielding Saghacetus 12% km or so west of Qasr el-Sagha temple but rather interpretation of paleoenvironment . Barnes and Mitchell (1978) published the most recent because there are many. The type locality must be at or review of Egyptian Eocene Cetacea. Domning et al. somewhere near Garet el-Esh. A very good partial (1982) reviewed type localities of Egyptian Eocene skeleton of Saghacetus has been found there in BlanckenSirenia. It was standard practice at the time to regard horn's zone 11-4 (see Fig. 32) rather than 11-5a, meaning the Bartonian stagelage as late Eocene. In preparing this that the exact level yielding the type is uncertain. summary, I have studied original specimens of all of the However, there is no question that the type came from existing Egyptian Eocene cetacean types in Cairo, the Temple Member of the Qasr el-Sagha Formation or London, Berlin, Munich, and Stuttgart, and I have seen that its age is late Priabonian. Stromer (1903a,b) described the archaeocete specimens sirenian types in Cairo, London, and Stuttgart. found during his 1902 expedition to Egypt with Blanckenhorn. These included a good skull of Saghucetus osiris (since destroyed) from a hard bed in BlanckenCETACEA horn's zone 11-5a between Gebel Hameier (Fig. 15) and Korallenhiigel (Fig. 16) north of Dimeh. In addition, The first specimens of Eocene cetaceans collected from Stromer (1903b) named a new species, Zeuglodon zitteli, Egypt were found by G. Schweinfurth on the island of based on fragmentary remains he collected at ZeuglodonGeziret el-Qarn in Birket Qarun. These were described berg (Figs. 18, 19; these were first identified as Zeug-
lodon osiris in Blanckenhorn, 1903, p. 391). The type specimen of Zeuglodon zitteli is a fragmentary rostrum and three articulated cervical vertebrae (illustrated by Stromer, 1903b, figs. 1 and 2). These are said to have come from the same stratigraphic interval as the type of Saghacetus osiris, possibly from the same locality, and they are indistinguishablefrom comparable remains of S.
osiris. Zeuglodon isis (now Basilosaurus isis, see Gingerich et al., 1990) was named by Beadnell in Andrews (1904, p. 214). Andrews described the best specimen, a dentary, giving its total length as 83 cm and stating that this "may be taken as the type," thus making the name available. Andrews (1904) gave the type locality as "Birket-elQerun beds" of Fayum. Beadnell (1905, p. 44) added that the type came from "cliffs near the west end of the lake." The type is figured in Andrews (1906, fig. 78). Beadne117s(1905) section of the Birket Qarun Formation at the west end of lake Birket Qarun is shown in Figure 25. The type specimen of Basilosaurus isis may have come from the top of the Gehannam Formation, from the Birket Qarun Formation, or even conceivably (but improbably) from what is here called the lower part of the Qasr el-Sagha Formation. Whether the specimen came from the Gehannam Formation or the Birket Qarun Formation at the west end of Birket Qarun matters little as the age of the type is likely to be earliest Priabonian in either case (the uppermost Gehannam Formation in this area is probably Priabonian in age-j?de Abdou and Abdel-Kireem, 1975; Haggag, 1990). Fraas (1904a, pp. 200-201, interpreted with the help of E. Stromer) gave stratigraphic levels for the type specimens of Protocetus atavus and Mesocetus schweinfirthi (the latter was moved to Eocetus by Fraas, 1904b). Both came from Gebel Mokattam. According to Fraas, the type of P. atavus came from Schweinfurth's (1883) bed Ale, said to be equivalent to Mayer-Eymar's horizon Ia and Blanckenhorn's Gizehensis bed 1-2, and it was found 3 m above the lowest bed with bony fish and sharks. There are some inconsistencies in Gebel Mokattam sections measured by different authors, and Blanckenhorn's reference section for the lower Mokattam stage was at Wadi el-Sheikh rather than Gebel Mokattam. Consequently, Schweinfurth's section is probably the best to use for reference in interpreting Fraas' stratigraphic information. The precise locality where the type was found is unknown, but it may have been Schweinfurth's locality X I near the old grave-mosque known as GamaTingiye. The likely position of the type of Protocetus atavus in the Lower Building Stone Member of the Mokattam Formation is shown with a diamond in Figure 5. This interval is probably middle Lutetian in age (Fig. 52). Protocetus is distinctly primitive among Egyptian archaeocetes in retaining a protocone on upper molars and in retaining a sacral vertebra with articular
surfaces for the pelvis. This stage of evolution is consistent with a middle Lutetian age. The type skull of Eocetus schweinfirthi came from about 8 meters below the upper boundary of the lower Mokattam in a hard gray-white limestone above a Schizaster bed. This is full of mollusks and small nummulites, like the upper part of Schweinfurth's zone Ala and Blanckenhorn's zone 1-5 (Fraas, 1904a, p. 201). The likely position of the type of Eocetus schweinfirthi in the Giushi Formation is shown with a diamond in Figure 5. This interval is probably Bartonian in age (Fig. 52). The most distinctive specimen of Eocetus described by Fraas (1904a) is an upper molar retaining three roots and a well developed (if worn) protocone cusp. The molar presumably came from the same stratigraphic interval as the type skull, and it indicates that Eocetus was significantly more primitive and thus probably older (early Bartonian?) than any specimens known to date from Wadi Hitan. Prozeuglodon atrox was named by Andrews (1906), based on a type skull and lower jaw collected by Beadnell from "Birket-el-Qurun beds" in "a valley about 12 kilometers W. S.W. of the hill called Gar-el-Gehannem" (Andrews, 1906, p. 255). This valley is Zeuglodon Valley, or what is here called Wadi Hitan [Valley of Whales]. The type specimen of P. atrox retains deciduous premolars, showing that it was a juvenile, and subadult specimens indistinguishable from the type of P. atrox are common in both the Gehannam and Birket Qarun formations in Wadi Hitan. Beadnell (1905) did not always distinguish the Gehannam and Birket Qarun formations lithologically and they overlap some in time. Thus the age of the type specimen of P. atrox may be either latest Bartonian or earliest Priabonian. Dart (1923) named three archaeocete species from Fayum based on brain size and form as evidenced by endocasts. These are problematical because Dart had no first-hand knowledge of Fayum stratigraphy nor any knowledge of fossil preservation (and distortion) there. Dart's understanding of type localities and age of the fossils he studied came either second-hand from Andrew~,who published an accompanying note on the skulls from which Dart's endocasts were taken (written some seventeen years after completing his study of Fayum mammals; see Andrews, 1923), or third-hand from Beadnell via Elliot Smith over a period of almost twenty years. In recent years we have collected some forty archaeocete endocasts from the Gehannam, Birket Qarun, and Qasr el-Sagha formations, in various states of preservation, and these provide some basis for rational interpretation of the systematic position of Dart's species. Zeuglodon sensitivus is the first species named by Dart (1923, p. 618), and the type is an endocast said to have come from "the Egyptian Fayum at the locality known as the Gar-el-Gehannem" w e Beadnell as-told-to Elliot
Table 1. Type specimens and type localities of Eocene Cetacea described from Egypt.
Genus and species
Author
Type
Type locality
1. Zeuglodon osiris Dames 1894 [here placed in new genus Saghacetd]
MNB2 28388 [Berlin 161
g-Berge 12% km im Westen vom alten Tempelbau, AAAB [Schweinfurth (1886, p. 139), upper Qasr el-Sagha Fm.]
Stromer 1903 2. Zeuglodon zitteli [synonym of Saghucetus osiris]
UISPM 'Mn.3'
Gleichen Horizont und demselben Fundort [as Berlin 161 [upper Qasr el-Sagha Fm.]
~eadnell~ 3. Zeuglodon isis [now placed in Basilosaurus Harlan]
CGM 10208
Birket Qarun cliffs near west end of lake [loc. from Beadnell (1905, p. 44), Birket Qarun Fm.]
4. Protocetus atavus
Fraas 1904
SMNS 11085
Mokattam, Schweinfurth Ale = Blanckenhom 1-2 [top of Lower Building Stone Mbr. of Mokattam Fm.]
5. Mesocetus schweinfurthi Fraas 1904 [now placed in Eocetus Fraas]
SMNS 10986
Mokattam, Schweinfurth Ala = Blanckenhorn 1-5 [Giushi Fm.]
6. Prozeuglodon atrox
CGM 9319
Birket Qamn beds 12 km WSW of Garet Gehannam [Birket Qarun Fm.]
7. Zeuglodon sensitivus Dart 1923 [synonym of Saghacetus osiris]
NHML 12123
Fayum, "Garet Gehannam" [see text, prob. from upper Qasr el-Sagha Fm. near Qasr el-Sagha]
8. Zeuglodon intermedius Dart 1923 [synonym of Prozeuglodon atrox]
NHML 10173
Fayum, possibly Birket Qarun beds at west end of lake Vide Andrews (1923, p. 648); Birket Qarun Fm.]
9. Zeuglodon elliotsmithii Dart 1923 [synonym of Saghacetus osiris]
NHML 12066 [cast]
Qasr el-Sagha beds north of Birket Qarun [see Elliot Smith, 1903; Andrews, 1906, p. 2361
10. Prozeuglodon stromeri Kellogg 1928 [now placed in Dorudon]
UISPM 'Mn.9' [destroyed]
Feinktirnigem graugriinlichem Sandstein der Saghastufe, Fayum [Stromer (1908, p. 110); u. Qasr el-Sagha Fm.]
Andrews 1906
Inf. int.'
'Informal faunal interval designation, explained in text. 2~bbreviationsare as follows: CGM - Cairo Geological Museum, Cairo; MNB - Museum fur Naturkunde der Humboldt-Universitit, Berlin; NHML - Natural History Museum, London; SMNS - Staatliches Museum fiir Naturkunde, Stuttgart; UISPM - UniversititsInstitut und Staatssammlung fur Pal2ontologie und Historische Geologic, Munich. 3Saghacetusnew genus, type species Zeuglodon osiris Dames 1894; differs from Dorudon and all other archaeocetes in having thoracic vertebrae normally proportioned but posterior lumbars and anterior caudals distinctly long in comparison to centrum height and breadth. Saghucetus osiris is easily recognized as the smallest archaeocete known from Fayum, and it is only known from the upper Qasr el-Sagha Formation. Two specimens with associated skulls, dentaries, and good axial skeletons have been prepared (University of Michigan 83905 and 97550). These and other specimens will be described in a later publication. 41n Andrews (1904): this was published in the May issue of Geological Magazine for 19aQ and evidently predates publication of Protocetus atavus and Mesocetus [Eocetus] schweinfurthi in Fraas (1904a)
Smith as-told-to Dart; see Dart, 1923, p. 616). This type is one of the best natural endocasts ever collected in Fayum because it retains excellent surface detail and appears to be free from compression or other distortion. The quality of the endocast by itself suggests preservation on a lime-rich hard bed in the Temple Member of the Qasr el-Sagha Formation. Dart gave the volume of this endocast as 490 cc (Dart, 1923, p. 634), which is virtually identical to the value of 480 cc he gave for
"Zeuglodon"osiris. None of the many endocasts preserved in Wadi Hitan is this small. Beadnell (1905, p. 39) mentioned that poorly preserved skeletons of Zeuglodon isis are fairly common in the Gehannam Formation near Garet G e h a ~ a m however, ; that species has much larger endocasts (on the order of 2100 cc) and specimens at Garet Gehamam are so poorly preserved that it is unlikely any was ever considered worth collecting. Dart's type of Zeuglodon sensitivus is almost
certainly an endocast of Saghacetus osiris, differing from others of the species in being full grown and exceptionally well preserved, and it probably came from the Temple Member of the Qasr el-Sagha Formation somewhere along the Qasr el-Sagha escarpment. Zeuglodon intemdius is the second species named by Dart (1923, p. 629). This was based on an artificial endocast made from a skull described briefly by Andrews (1923). The type skull appears to be adult because the occiput is high and narrow, the rostrum is long and narrow, the frontal shield is broad, cranial sutures are closed, and premolar alveoli are adult in conformation. Dart (1923) gave the endocranial volume as 785 cc, which is in the range of Prozeuglodon an-ox. Andrews (1923) reported the total length of the skull as 550 mm, but Kellogg (1936, p. 246) independently measured this as 795 mm, which again is within the range of P. atrox. Regarding the type locality, Andrews (1923, p. 648) wrote that the type skull: seems from the nature of the matrix to have been obtained from the Birket-el-Qurun beds at the western end of the lake from an horizon intermediate between those from which the other species were found. This, however, in the absence of definite information from the collector is not certain. Dart's endocranial volume, Kellogg's skull length, and Andrews' inferred stratigraphic interval and geographic locality are consistent in indicating that Zeuglodon intemdius is a junior synonym of Prozeuglodon atrox. Zeuglodon elliotsmithii is the third species named by Dart (1923, p. 625), and the type is a natural endocast described by Elliot Smith (1903). Dart studied a plaster copy of the original endocast (now lost?), and the copy Dart studied is in the Natural History Museum, London. Elliot Smith (1903) stated that this specimen was found by Beadnell in 1902 at "the same locality" as the partial skull of Zeuglodon osiris described and illustrated by Andrews (1901, 1906), that is, in the Qasr el-Sagha beds north of Birket Qarun (Andrews, 1906, p. 236). Dart (1923) gave the endocranial volume of this specimen as 310 cc, which is smaller than the endocranial volume of adult specimens of the smallest species, S. osiris, known from Fayum, and the type of 2. elliotsmithii is almost certainly an artificially compressed endocast, a weathered endocast, or a subadult endocast of Saghacetus osiris. The last archaeocete species named from Fayum is Prozeuglodon stromeri Kellogg 1928, later moved to Dorudon (Kellogg, 1936, p. 203). The type specimen is Munich 9 [Mn. 9, destroyed], which Stromer (1908, p. 110) had earlier identified as Zeuglodon osiris. According to Stromer, the specimen consisted of:
weisslicheReste eines nicht ausgewachsenenIndividuums aus feinkiirnigem, graugriinlichem, weichem Sanhtein der Saghmtufe [whiteish remains of an immature individual from fmegrained, gray-green, soft sandstone of the Qasr el-Sagha stagel Many of the characteristics Kellogg (1936) listed as differences from Saghacetus osiris are characteristics that distinguish subadult from adult individuals, but comparable molar measurements (Kellogg, 1936, p. 206) show Dorudon stromeri to have been about 50% larger than Saghacetus osiris in most linear dimensions (and new specimens show the two species to have had differently proportioned lumbar and caudal vertebrae). The type specimen of Dorudon stromeri came from the Temple Member of the Qasr el-Sagha Formation and it is thus late Priabonian in age. To summarize, one archaeocete genus and species, Protocetus atavus, is known from the middle Lutetian of Egypt. Another genus and species, Eocetus schweinfurthi, is known from the Bartonian. Two genera and species, Basilosaurus isis and Prozeuglodon atrox, have been named from the Bartonian-Priabonian transition, and two species, Saghacetus osiris and Dorudon stromeri, are known from the late Priabonian. SIRENIA Richard Owen (1875) named the first Eocene sirenian described from Egypt, Eotherium aegyptiacum, based on a specimen presented by a Dr. Grant of Cairo. Palmer (1899) noted that Eotherium was preoccupied and placed this in the new genus Eotheroides. The type included fragments of the basicranium and a well p r e s e ~ e d endocranial cast. This was found in: the white, compact, fine-grained, calcareous stone of the Nummulitic Eocene Tertiary period, now quarried extensively in the Mokattam cliffs, south of Cairo, for the buildings in progress in the modern part of that city. The type of E. aegyptiacum is almost certainly from the Lower Building Stone Member of the Mokattam Formation, and it may have been found at or near Schweinfurth's locality XI1 (Gama-Tingiye). Fraas (1904a, p. 201) mentioned Eotherium aegyptiacum Owen as coming from 4 m above the level of Protocetus atavus, but it is not clear whether he was referring to Owen's original type or to referred specimens collected later. The probable position of the type specimen of Eotheroides aegyptiacum in the Lower Building Stone Member of the Mokattam Formation is shown with a diamond in
Table 2. Type specimens and type localities of Eocene Sirenia described from Egypt.
Genus and species
Author
1. Eotherium aegyptiacurn
Owen 1875 [now placed in Eotheroides Palmer]
Type
Type locality
NHML2 46722
White nummulitic limestone of Mokattam cliffs K. Building Stone Mbr. of Mokattam Fm.]
2. Manatus coulornbi
Filhol 1878 MNHN [indet. or synonym of Protosiren fraasi?]
Inf. int.'
A
Canikres de Mokattam prCs du Caire wokattam Fm.]
3. Eosiren libyca
Andrews 1902
CGM 10054
Qasr el-Sagha beds, Fayum [upper Qasr el-Sagha Fm. ]
4. Protosiren fiaasi
Abel 1907
CGM 10171
Mokattam Hills, probably same as type of E. aegyptiacum Vide Andrews (1906, p. 204), LBS, Mokattam Fm.]
A
SMNS
Westlich von Dimeh, Fayum, Horizont 5a der obern Mokattamstufe [upper Qasr el-Sagha Fm.]
F
5. Archaeosiren stromeri
Abel 1913 [synonym of Eosiren libyca?]
6. Eotherium (Eosiren) abeli Sickenberg 1934 UISPM [synonym of Protosiren fraasi?] [destroyed]
Unter Mokattam "hinter den Khalifengrlbern" wokattam Fm.]
A or B
Zdanslcj 1938 CGM? 7. Eotherium majus [synonym of Eotheroides aegyptiacum?]
Niveau "Baustein" des Gebel Mokattam Ost von Kait Bey wokattam Fm.]
A or B
'Informal faunal interval designation, explained in text. 2~bbreviationsare as follows: CGM - Cairo Geological Museum, Cairo; MNHN - MusCum National d'Histoire Naturelle, Paris; NHML - Natural History Museum, London; SMNS - Staatliches Museum fur Naturkunde, Stuttgart; UISPM - UniversiGts-Institut und Staatssammlung fur Palaontologie und Historische Geologie, Munich.
Figure 5. This, like the type of Protocetus atavus, is probably middle Lutetian in age (Fig. 52). Manatus coulombi was named by Filhol (1878) based on three teeth from the Mokattam quarries near Cairo. According to Filhol (1878, p. 124): Les dents de Manatus qui y ont t t t trouvtes ont t t t rencontrtes ri cinq metres de profondeur. La portion suptrieure du sol ttait formt par l'agglomtration de nummulites avec oursins et coquilles marines. C'est sous cette couche qu 'ont t t t dtcouverts divers dkbris de mammz~res.
[The teeth of Manatus found there have been found at a depth of five meters. The upper part of the soil was formed by an agglomeration of nummulites with marine echinoids and mollusk shells. Beneath this bed have been found various remains of mammals.]
Filhol mentioned a number of invertebrates, including "Conoclypeus" and Cerithium giganteum, but it is not clear that these came from the same level as the sirenian.
Cerithium is a form-genus applied to high-spired, turreted, nonumbilicate, variously sculptured gastropods. Oppenheim (1903- 1906)considered Mokattam Cerithium giganteum to belong in Cerithium (Campanile) lachensis Bayan. Whatever name is used, this species is distinctive in being very large (possibly 50 cm or more in height when complete). Fraas (1867, p. 144) considered Cerithium giganteum to be the most conspicuous mollusk in the building stone of Cairo, and recognized a distinct zone for it (Chapter 11). The type of Manatus coulombi undoubtedly came from the Mokattam Formation, but it may have come from either the Lower or Upper Building Stone. The teeth are relatively small (the largest lower molar measures 15 x 11 mm), but otherwise little can be said about them. The type specimen of Eosiren libyca named by Andrews (1902) is a nearly complete skull collected from Qasr el-Sagha beds north of Birket Qarun (Andrews, 1906). This is almost certainly from the Temple Member of the Qasr el-Sagha Formation and it is late Priabonian in age. The name Protosiren fiaasi was first published as a nomen nudum by Abel (1904), which explains how Fraas
(1904) was able to indicate that this species came from from Abel (1913) or Sickenberg (1934) need not concern the same stratigraphic level as the type of Protocetus us here. Abel (1913) states that the type came from atavus, but Abel provided no diagnosis or illustration, "Horizont 5a der oberen Mokattamstufe" west of Dimeh nor did he designate a type specimen. Abel's (1907) in Fayum, that is, Blanckenhorn's zone 11-5a (see Figs. study is taken as the first valid publication of Protosiren 15-18, 20, 32). The type specimen of Archaeosiren f r m i (following Sickenberg, 1934, p. 43; and Domning stromeri is late Priabonian in age, and this species is et al., 1982, p. 36). In the latter study, Abel made the probably a synonym of Eosiren libyca. Sickenberg (1934, p. 34) named a new species EotherCairo Geological Museum skull illustrated by Andrews (1906, fig. 66) the type. According to Andrews (1906, ium (Eosiren) abeli based on an isolated upper molar p. 204), this came from "limestones of the Mokattam (right M ~ from ) the lower Mokattam "hinter den KhalHills" and "probably the same [horizon] as ... the type ifengrabern" [behind the graves of the caliphs]. The of Eotherium aegyptiacum. " The mandible described graves of the caliphs are in the region in front of Gebel with this skull (Andrews, fig. 67) has since been com- Mokattam known as El-Khalifa or Qaitbai wait Bey], pared with Eotheroides aegyptiacum (Domning et al., north and east of the Cairo Citadel (Schweinfurth, 1883; 1982), reinforcing the idea that Eotheroides aegyptiacum Geological Survey of Egypt, 1983). This locality and Protosirenfraasi occur together in the upper part of information is ambiguous, but it probably means that the the Lower Building Stone Member of the Mokattam specimen came from the Mokattam Formation, making Formation. Thus the age of the type specimen of it Lutetian in age (Fig. 52). An isolated tooth is weakly diagnostic at best, but the small size of the type of P. fraasi is probably middle Lutetian. Priem (1907) described a good mandible of Protosiren E. abeli suggests that it may possibly be an upper molar fraasi from Gebel Mokattam sent to him by P. Teilhard, of Protosiren fraasi. The last species of Eocene sirenian named from Egypt, then professor at the Collkge de la Ste-Famille in Cairo. Priem indicated (p. 417) that this, like most of the Eotherium mujus described by Zdansky (1938), is also collection made by Teilhard, came from the "couches based on an isolated upper molar. This was found by J. supkrieures du Mokattam," which evidently means that Cuvillier "im Niveau des 'Bausteines' des Gebel Mokatthe specimen did not come from the Lower Building tam 0. von Kait Bey" [in the level of the 'Building Stone of the Mokattam Formation, as the type did, but Stone' of Gebel Mokattam east of Kait Bey]. The rather probably from the Upper Building Stone (or repository of the type is unknown, but Cuvillier and conceivably from what are today called Giushi and Zdansky were both lecturers at the Geological Institute, Maadi formations). The specimen has been important in Cairo University, and possibly the type is there. The comparisons made by Sickenberg (1934) and Domning et locality information is ambiguous, but it probably means al. (1982), and it is unfortunate that its provenance is so that the specimen came from the Mokattam Formation, making it Lutetian in age (Fig. 52). The large size of poorly known. Domning et al. (1982, p. 55 and fig. 34) described a the type of E. majus suggests that it may possibly be an mandible of Protosiren sp. said to come from the late upper molar of Eotheroides aegyptiacum. To summarize, there are clearly two sirenian genera Eocene Qasr el-Sagha Formation of Fayum. This specimen is actually from the Gehamam Formation or and species, Eotheroides aegyptiacum and Protosiren the Birket Qarun Formation of Wadi Hitan (Zeuglodon fraasi, known from the middle to late Lutetian at Gebel Valley), and it is latest Bartonian (middle Eocene) or Mokattam. One of these genera, Protosiren sp., has earliest Priabonian (late Eocene) in age. Protosiren is been reported from the late Bartonian or early Priabonian at Wadi Hitan in Fayum (and new collections there not known from the Qasr el-Sagha Formation. Abel (1913, p. 307) named a new sirenian genus and include Eotheroides). An additional genus and species, species Archaeosiren stromeri, based on two Stuttgart Eosiren libyca, is known from the late Priabonian in specimens, one a skull (lacking the lower jaw) with most Fayum. of the axial skeleton, and the other an isolated thoracic vertebra. Abel ranked the specimens by completeness, AGES AND PALEOENVIRONMENTS but here again he did not provide a diagnosis or illustration, nor did he explicitly state that the more complete Marine mammals are known from seven time intervals specimen is the type. Sickenberg (1934, p. 130) regarded Archaeosiren stromeri as a nomen nudum, but para- in the Paleogene of Egypt. For ease of reference, these doxically used the species name and credited it to Abel are designated informally A through G . Ages of A-C (Sickenberg synonymized Archaeosiren with Eotherium) . are based to some degree on the stage of evolution of Further, Sickenberg considered Abel to have provided cetaceans and sirenians coming from these intervals, but enough information to identify a specimen to which the D-G are based on independent evidence discussed in name belonged. Whether Archaeosiren stromeri dates Chapter V. Six of these intervals are Eocene and one is
CONCLUSIONS AND PROSPECTUS Eocene and Oligocene sedimentary rocks and depositional environments of northern Egypt are best interpreted in a dynamic stratigraphic context. The dynamic model proposed here has two componeats: (I) eissodic change in eustatic sea level, superimposed on (2) normal progradation of depositional facies on a passive continental margin. The sea of interest is Tethys, the continental margin is the northern margin of Africa, and the shoreline between them trended, generally, WSW-ENE across what is now northern Egypt. This trend, in part coincidentally, is also the trend of the best studied outcrops of Eocene and Oligocene sediments in Fayum and in the desert surrounding Gebel Mokattam east of Cairo. The most important changes in sedimentary facies on passively subsiding continental margins are seen in going offshore-onshore (or vice versa) rather than along the shore line, and much of the difficulty in understanding Fayum and Gebel Mokattam stratigraphy has come because many of the best outcrops are not perpendicular to the ancient shoreline but rather lie parallel to it. Further, these outcrops are generally eroded from the "back" (i.e., from the continental side), meaning that the present outcrop distribution of sedimentary facies is reversed from the original distribution of facies (offshoreonshore transects appear reversed), making the pattern of facies relationships more difficult to recognize. Figures 55 and 56 in Chapter VI show idealized reconstructions of sedimentary facies in NNW-SSE transects perpendicular to shoreline. These are dynamic in combining sea level change with progradation. They are idealized in the sense that consideration of sea level change has been limited to episodes of major change, progradation has been assumed to proceed at a constant rate, and local structural influences (as at Abu Roash) have been ignored. Figure 56 was constructed to show the vertical distribution of sedimentary facies observed in Fayum where
facies and formations are best exposed, and to show how the vertical distribution of facies relates to their offshoreonshore distribution. The extent to which the same model explains vertical and offshore-onshoredistributio~ of facies at Gebel Mokattam (Figure 55) is largely unknown, and further study east of Cairo will provide an important test of the general model, hopefully leading to refinement. Marine mammals, cetaceans and sirenians, are relatively common as fossils in nearshore deposits at Gebel Mokattam and in Fayum. These are often well preserved and very informative about evolutionary stages represented. It is impossible at present to make any real comparative interpretation of changing environments of cetaceans and sirenians because mammal-bearing intervals at Gebel Mokattam are older than those in Fayum, and they sample environments in deeper water farther offshore. They do not, at present, permit comparison of evolution in different environments through time. However, it is also true that much of the Eocene in Egypt remains to be prospected for marine mammals. Blanckenhorn (1900) reported finding Zeuglodon teeth at Wadi el-Sheikh in the Eastern Desert (Fig. 8) and marine mammals have been reported elsewhere in Egypt, but such leads have seldom been pursued. Finding new cetaceans and sirenians in new environments and new time intervals is largely a matter of effort-fossils are undoubtedly there to be collected. Archaeocetes were widely distributed and evolved rapidly in the Eocene. Consequently, cetacean fossils have considerable potential for broad-scale stratigraphic correlation within Egypt and between Egypt and other parts of the world. Eocene cetaceans and sirenians are also interesting because the two groups document a major evolutionary transition in the history of mammals, the transition from life on land to life in the sea, which took place in parallel in the two groups.
LITERATURE CITED
ABDEL-KIREEM, M. R. 1985. Planktonic foraminifera of Mokattam Formation (Eocene) of Gebel Mokattam, Cairo, Egypt. Revue de Micropal&ntologie, 28: 77-96. ABDEL-KIREEM, M. R., A. BLONDEAU, and K. M. SHAMAH. 1985. Les Nummulites de la 1ocalitBtype de la formation de Gehannam (Le Fayoum, Egypte). Bulletin de la Soci&B dlHistoire Naturelle de Toulouse, 121: 65-71. ABDOU, H. F., and M. R. ABDEL-KIREEM. 1975. Planktonic foraminifera1 zonation of the middle and upper Eocene rocks of Fayoum Province, Egypt. Revista Espaiiola de Micropaleontologia, 7: 15-64. ABEL, 0. 1904. Die Sirenen der mediterranen Tertiarbildungen ijsterreichs. Abhandlungen der Kaiserlich-Kiiniglichen Geologischen Reichsanstalt, Wien, 19 (2): 1-223. ABEL, 0. 1907. Die Morphologie der Hiiftbeinrudimente der Cetaceen. Denkschriften der Mathematisch-Naturwissenschaftlichen Klasse der Kaiserlichen Akademie der Wissenschaften, Wien, 81: 139-195. ABEL, 0. 1913. Die eocanen Sirenen der Mittelrneerregion, erster Teil: der Schadel von Eotherium aegyptiacum. Palaeontographica, 59: 289-320. ABERHAN, M., and F. T. FURSICH. 1991. Paleoecology and paleoenvironments of the Pleistocene deposits of Bahia la Choya (Gulf of California, Sonora, Mexico). Zitteliana, Miinchen, 18: 135-163. AIGNER, T. 1982. Event-stratification in nummulite accumulations and in shell beds from the Eocene of Egypt. In: G. Einsele and A. Seilacher (eds.), Cyclic and Event Stratification. Springer, Berlin, New York, 248-262. AIGNER, T. 1983. Facies and origin of nummulitic buildups: an example from the Giza Pyramids plateau (middle Eocene, Egypt). Neues Jahrbuch f i r Geologie und Palaontologie, Abhandlungen, Stuttgart, 166: 347-368. ANDREWS, C. W. 1901. Preliminary note on some recently discovered extinct vertebrates from Egypt. Gwlogical Magazine, Decade N, 8: 436-444. ANDREWS, C. W. 1902. Preliminary note on some recently discovered extinct vertebrates from Egypt (Part 111). Geological Magazine, new series (IV), 9: 291-295. ANDREWS, C. W. 1904. Further notes on the mammals of the Eocene of Egypt, Part 111. Gwlogical Magazine, new series (V), 1: 211-215. ANDREWS, C. W. 1906. A descriptive catalogue of the Tertiary Vertebrata of the Fayum, Egypt. British Museum (Natural History), London, 324 pp. ANDREWS, C. W. 1923. Note on the skulls from which the endocranial casts described by Dr. Dart were taken. Proceedings of the Zoological Society of London, 1923: 648-652.
AWAD, G. H., and R. SAID. 1966. Egypt. Lexique Stratigraphique International, 4, fasicule 4b: 1-73. BARN=, L. G., and E. MITCHELL. 1978. Cetacea. In: V. J. Maglio and H. B. S. Cooke (eds.), Evolution of African Mammals. Harvard University Press, Cambridge, 582-602. BARRON, T. 1907. The Topography and Geology of the District between Cairo and Suez. Survey Department of Egypt, Cairo, 133 pp. BAUERMAN, H., and C. LE NEVE FOSTER. 1869. On the occurrence of celestine in the nummulitic limestone of Egypt. Proceedings of the Geological Society of London, 24: 40-44. BEADNELL, H. J. L. 1901. The Fayum depression: a preliminary notice of the geology of a district in Egypt containing a new Palaeogene vertebrate fauna. Geological Magazine, Decade N , 8: 540-546. BEADNELL, H. J. L. 1905. The topography and geology of the Fayum Province of Egypt. Survey Department of Egypt, Cairo, 101 pp. BEHRENSMEYER, A. K. 1978. Taphonomic and ecologic information from bone weathering. Paleobiology, 4: 150-162. BERGGREN, W. A., D. V. KENT, J. J. FLYNN, and J. A. VAN COUVERING. 1985. Cenozoic geochronology. Geological Society of America Bulletin, 96: 1407-1418. BLANCKENHORN, M. 1900. Neues zur Geologie und Palaontologie Aegyptens. 11. Das Palaeogen. Zeitschrift der Deutschen Geologischen Gesellschaft, 52: 403-479. BLANCKENHORN, M. 1903. Neue geologisch-stratigraphische Beobachtungen in Aegypten. Sitzungsberichte der Mathematisch-physikalischen Classe der Kijniglichen bayerischen Akademie der Wissenschaften, Miinchen, 32: 353-433. BLANCKENHORN, M. 1921. Aegypten. In: G. Steinmann and 0. Wilckens (eds.), Handbuch der regionalen Geologie (Heft 23). Carl Winters UniversitZtsbuchhandlung, Heidelberg, 244 PP. BLOW, W. H. 1979. The Cainozoic Globigerinida (2 vols.). E. J. Brill, Leiden, 1413 pp. BOLLI, H. M. 1957. Planktonic foraminifera from the Eocene Navet and San Fernando formations of Trinidad, B. W. I. Bulletin of the U. S. National Museum, 215: 155-172. BOUKHARY, M. A., and W. ABDELMALIK. 1983. Revision of the stratigraphy of the Eocene deposits of Egypt. Neues Jahrbuch fir Geologie und PalZontologie, Monatshefte, Stuttgart, 1983: 321-337. BOWEN, B. E., and C. F. VONDRA. 1974. Paleoenvironmental interpretations of the Oligocene Gabal el Qatrani Formation, Fayum Depression, Egypt. Annals of the Geological Survey of Egypt, 4: 115-138.
BOWN, T. M., M. J. KRAUS, S. L. WING, J. G. FLEAGLE, B. H. TIFFNEY, E. L. SIMONS, and C. F. VONDRA. 1982. The Fayum primate forest revisited. Journal of Human Evolution, 11: 603-632. B O W , T. M., and M. J. KRAUS. 1988. Geology and paleoenvironment of the Oligocene Jebel Qatrani Formation and adjacent rocks, Fayum Depression, Egypt. U.S. Gwlogical Survey Professional Paper, 1452: 1-60. B U S I E R , M. D. 1975. An outline history of seagrass communities. Palawntology, 18: 681-702. CUVILLIER, J. 1930. Revision du Nummulitique Egyptien. Memoires de 1'Institut d'Egypte, 16: 1-371. DAMES, W. B. 1883a. Ein Epistropheus von Zeuglodon sp. Sitzungsberichte der Gesellschaft naturforschender Freunde, Berlin, 1883: 3. DAMES, W. B. 1883b. Ueber eine tertiar Wirbelthierfauna von der westlichen Insel der Birket-el-Qurun. Sitzungsberichte der Koniglich-preussischen Akademie der Wissenschaften, Berlin, 1883: 129-153. DAMES, W. B. 1888. Ambiypristis cheops nov. gen. nov. sp. aus dem Eocln Aegyptens. Sitzungsberichte der Gesellschaft naturforschender Freunde, Berlin, 1888: 106-109. DAMES, W. B. 1894. Uber Zeuglodonten aus Aegypten und die Beziehungen der Archaeoceten zu den iibrigen Cetaceen. Geologische und Palaontologische Abhandlungen, Jena, 5: 189222. DART, R. A. 1923. The brain of the Zeuglodontidae (Cetacea). Proceedings of the Zoological Society of London, 1923: 615654. DOMNING, D. P. 1981. Sea cows and sea grasses. Paleobiology, 7: 417-420. DOMNING, D. P., G. S. MORGAN, and C. E. RAY. 1982. North American Eocene sea cows (Mammalia: Sirenia). Smithsonian Contributions to Paleobiology, 52: 1-69. ELLIOT SMITH, G. 1903. The brain of the Archaeoceti. Proceedings of the Royal Society of London, 71: 322-331. FARAG, I. A. M., and M. M. ISMAIL. 1955. On the structure of Wadi Hof area (northeast of Helwan). Bulletin de 1'Institut du Desert d'Egypte, Heliopolis, 5: 179-192. FARAG, I. A. M., and M. M. ISMAIL. 1959. Contribution to the stratigraphy of the Wadi Hof area. Bulletin of the Faculty of Sciences, Cairo University, 34: 147-168. FILHOL, H. 1878. Note sur la dhouverte d'un nouveau Mammifere marin (Manatus coulombs] en Afrique dans les camtres de Mokattam prts du Caire. Bulletin de la Societ6 Philomathique de Paris, SCrie 7, 2: 124-125. FLEAGLE, J. G., T. M. BOWN, J. D. OBRADOVICH, and E. L. SIMONS. 1986a. How old are the Fayum primates? In: J. G. Else and P. C. Lee (eds.), Primate Evolution. Cambridge University Press, Cambridge, 3-17. FLEAGLE, J. G., T. M. BOWN, J. D. OBRADOVICH, and E. L. SIMONS. 1986b. Age of the earliest African anthropoids. Science, 234: 1247-1249. FOURTAU, R. 1897. Note sur la stratigraphic du Mokattam. Bulletin de la Societe Gwlogique de France, Strie 3, 25: 208-21 1. FOURTAU, R. 1899. Note sur un nouveau gisement depoissons fossiles aux environs des Pyramides de Ghizeh. Bulletin de la Socikte Gwlogique de France, SCrie 3 , 27: 237-240. FOURTAU, R. 1900. Observations sur les terrains Eocknes et Oligoctnes d'Egypte. Bulletin de la Societe Gwlogique de France, S6rie 3, 27: 480-491.
FOURTAU, R. 1913. Catalogue des Invert&& fossiles de l'figypte reprksentes dans les collections du M u s k s d e G h logie au Caire. SCrie I. Terrains tertiaires, lkre partie: &hinoides wcknes. Egyptian Survey Department, Cairo, 1-93. FRAAS, E. 1904a. Neue Zeuglodonten aus dem unteren Mittelwcin vom Mokattam bei Cairo. Geologische wnd Paliontologische Abhandlungen, Jena, Neue Folge, 6: 197-220. FRAAS, E. 1904b. Neue Zeuglodonten aus dem unteren Mitteleocln vom Mokattam bei Cairo. Geologisches Zentralblatt, Leipzig, 5: 374. FRAAS, 0. 1867. Aus dem Orient. Geologische Beobachtungen am Nil, auf der Sinai-Halbinsle und in Syrien. Ebner & Seubert, Stuttgart, 222 pp. FURSICH, F. T. 1979. Genesis, environments, and ecology of Jurassic hardgrounds. Neues Jahrbuch f i r Geologie und Paliontologie, Abhandlungen, Stuttgart, 158: 1-63. GEOLOGICAL SURVEY OF EGYPT. 1981. Geologic Map of Egypt, Scale 1:2000000. Egyptian Gwlogical Survey and Mining Authority, Ministry of Industry and Mineral Resources, Cairo, 1 sheet. GEOLOGICAL SURVEY O F EGYPT. 1983. Geological Map of Greater Cairo Area, Scale 1:100000. Egyptian Geological Survey and Mining Authority, Ministry of Petroleum and Mineral Resources, Cairo, 1 sheet. GINGERICH, P. D., B. H. SMITH, and E. L. SIMONS. 1990. Hind limbs of Eocene Basilosaurus: evidence of feet in whales. Science, 249: 154-157. HAGGAG, M. A. Y. 1985. Middle Eoceneplanktonic foraminifera from Fayoum area, Egypt. Revista Espafiola de Micropalwntologia, 17: 27-40. HAGGAG, M. A. Y. 1989. Planktonic foraminiferal zonation and evolutionary groups of the middle Eocene in the Nile Valley, Egypt. Neues Jahrbuch fur Geologie und Paliontologie, Abhandlungen, Stuttgart, 178: 109-132. HAGGAG, M. A. 1990. Globigerinapseudoampliaperturazone, a new late Eocene planktonic foraminiferal zone (Fayoum area, Egypt). Neues Jahrbuch f i r Geologie und PaBontologie, Monatshefte, Stuttgart, 1990: 295-307. HAGGAG, M. A. Y., and H. LUTERBACHER. 1991. Middle Eocene planktonic foraminiferal groups and biostratigraphy of the Wadi Nukhul section, Sinai, Egypt. Neues Jahrbuch f i r Geologie und Palaontologie, Monatshefte, Stuttgart, 1991: 319-334. HAQ, B. U., J. HARDENBOL, and P. R. VAIL. 1987. Chronology of fluctuating sea levels since the Triassic. Science, 235: 1156-1167. HASSAAN, M. M., A. M. HASSANEIN, M. H. MOHAMMAD, and S. A. ABD EL MONEIM. 1990. Lithostratigraphical and microfacies studies on the Mokattam and Maadi Formations, Gabal Mokattam area, Egypt. Annals of the Geological Survey of Egypt, 16: 229-233. HILL, D., and J. W. WELLS. 1956. Hydroidea and Spongiomorphida. In: R. C. Moore (ed.), Treatise on Invertebrate Paleontology, Part F, Coelenterata. Geological Society of America and University of Kansas Press, Lawrence, 81-89. HOYT, J. H. 1967. Bamer island formation. Geological Society of America Bulletin, 78: 1125-1136. HUME, W. F., T. W. MADGWICK, F. W. MOON, and H. SADEK. 1920. Preliminary geological report on Gebel Tanka area. Petroleum Research Bulletin, Government Press, Cairo, 4: 1-16.
HUTCHINGS, P., and P. SAENGER. 1987. Ecology of Mangroves. University of Queensland Press, St Lucia (Australia), 388 pp. ISKANDER, F. 1943. Geological survey of the Gharag el Sultani sheet no. 68/54. Standard Oil Company, Egypt S. A., Reports, 51: 1-29. ISMAIL, M. M., and M. R. ABDEL-KIREEM. 1975. Contribution to the stratigraphy of the Fayum Province. Bulletin of the Faculty of Science, Alexandria University (1971), 11: 57-63. KAPPELMAN, J. 1991. Paleomagnetic stratigraphy and age estimates for the Fayum primates. American Journal of Physical Anthropology, Supplement 12 (Abstracts): 102-103. KELLOGG, A. R. 1928. The history of whales-their adaptation to life in the water. Quarterly Review of Biology, 3: 29-76, 174-208. KELLOGG, A. R. 1936. A review of the Archaeoceti. Carnegie Institution of Washington Publications, 482: 1-366. KHASHAB, B. E. 1974. Review of the early Tertiary eutherian faunas of African mammals in Fayum Province, Egypt. Annals of the Geological Survey of Egypt, 4: 95-114. KRASHENINNIKOV, V. A., and V. P. PONIKAROV. 1965. Zonal stratigraphy of Paleogene in the Nile Valley. Geological Survey of Egypt, Cairo, Paper no., 32: 1-26. MAYER-EYMAR, K. 1883. Die Versteinerungen der tertiaeren Schichten von der westlichen Insel im Birket-el-QurCn-See (Mittel-Egypten). Palaeontographica, 30: 67-77. MAYER-EYMAR, K. 1886. Zur Geologie Egyptens. Vierteljahrsschrift der Naturforschenden Gesellschaft in Zurich, 31: 24 1-267. MAYER-EYMAR, K. 1893. Le Ligurien et Tongrien en Bgypte. Bulletin de 1'Institut de Egypte, 4: 365-380. MAYER-EYMAR, K. 1895. Quelques mots sur no,uvelles recherches relatives au Ligurien et au Tongrien d'Egypte. Bulletin de 1'Institut kgyptien, Cairo, Troisitme SBrie, 5: 215-220. MAYER-EYMAR, K. 1896. L'extension du Ligurien et Tongrien en Egypte. Bulletin de 1'Institut Bgyptien, Cairo, Troisitme SBrie (1895), 6: 85-96. MAYER-EYMAR, K. 1898. Neue Echiniden aus den Nummulitengebilden Egyptens. Vierteljahrsschrift der Naturforschenden Gesellschaft in Zurich, 43: 46-55. MAYER-EYMe, K. 1900. Un singulier cBphalopode de 1'Eoctne de 1'Egypte (Kerunia cornura n. g. et sp.). Eclogae Geologicae Helvetiae, Lausanne, 6: 120-121. McCOY, E. D., and K. L. HECK. 1976. Biogeography of corals, seagrasses, and mangroves: an alternative to the center of origin concept. Systematic Zoology, 25: 201-210. MENEISY, M. Y. 1990. Vulcanicity. In: R. Said (ed.), The Geology of Egypt. Balkema, Rotterdam, 157-172. MOUSTAFA, Y. S. 1974. Critical observations on the occurrence of Fayum fossil vertebrates. Annals of the Geological Survey of Egypt, 4: 41-78. ODIN, G. S., and A. MONTANAN. 1989. Age radiomitric et stratotype de la limite Boctne Oligocene. Comptes Rendus de 1'Acadkmie des Sciences, Paris, SBrie 11, 309: 1939-1944. OPPENHEIM, P. 1903-1906. Zur Kenntnis alttertilr Faunen in Egypten. Palaeontographica, Stuttgart, 30: 1-164 (1903), 165-348 (1906). OSBORN, H. F. 1907a. The Fayum expedition of the American Museum. Science, 25: 513-516. OSBORN, H. F. 190%. Hunting the ancestral elephant in the Fayr~mdesert. Century Magazine, 74: 815-835.
OSBORN, H. F. 1908. New fossil mammals from the Fayum Oligocene, Egypt. Bulletin of the American Museum of Natural History, 24: 265-272. OWEN, R. 1875. On fossil evidences of a sirenian mammal (Eorherium aegyptiacum) from the nummulitic Eocene of the Mokattam cliffs, near Cairo. Quarterly Journal of the Geological Society of London, 31: 100.105. PALMER, T. S. 1899. Trouessart's 'Catalogus Mammalium'. Science, 10: 491-495. PITMAN, W. C. 1978. Relationship between eustacy and stratigraphic sequences of passive margins. Geological Society of America Bulletin, 89: 1389-1403. PRIEM, F. 1897a. Poissons de 1'8octne du Mont Mokattam (8gypte). Bulletin de la Sociitk Gtklogique de France, SBrie 3, 25: 212-227. PRIEM, F. 189%. Note sur Propristis Dames du Tertiaire infkrieur d9figypte. Bulletin de la Soci&6 Gblogique de France, 25: 228-232. PRIEM, F. 1907. Sur des vtrtebrh de 1'8ocbne d9ggypte et de Tunisie. Bulletin de la SociktB Gtklogique de France, Strie 4, 7: 412-419. RASMUSSEN, D. T., T. M. BOWN, and E. L. SIMONS. 1992. The Eocene-Oligocene transition in continental Africa. In: D. R. Prothero and W. A. Berggren (eds.), EoceneOligocene Climatic and Biotic Evolution. Princeton University Press, Princeton, 548-566. ROMAN, J., and A. STROUGO. 1988. Echinoides de I'etage Mokattamien (Eocene moyen et superieur) de la region du Grand Caire (Egypte). Bulletin du Museum National D'Histoire Naturelle,Paris, 10: 137-161. SAID, R. 1962. The Geology of Egypt. Elsevier Publishing Company, Amsterdam and New York, 377 pp. SAID, R. 1990. Cenozoic. In: R. Said (ed.), The Geology of Egypt. A. A. Balkema, Rotterdam, 451-486. S C H ~ E R W. , 1972. Ecology and Palawecology of Marine Environments (translation of Actuo-pallontologie nach Studien in der Nordsee, 1962). University of Chicago Press, Chicago, 568 pp. SCHLOSSER, M. 1911. Beitrgge zur.l
